While it's generally accepted that contentment and peace of mind are the result of a zen-like state of acceptance, there's not a lot of real people who can accept everything and just be happy. We're plagued by worries and despite wanting to accept them, they usually don't go away, but I'm here to tell you that your worries are a good thing.
In order to understand why, let's do a quick thought experiment. Let's say there's two people. Joe and Bob. Joe just got home from work and wants to relax. He has a dinner without rushing himself, watches TV, then goes to bed. Bob also just got home from work, but he heads to the gym first, then eats a quick dinner because he's tired, then goes to bed. Who sleeps better?
While there's no guarantee, I think must of us can agree that Bob will get the better sleep because he's more tired than Joe, he went to the gym, therefore his body will be happier to sleep, whereas Joe might roll around in bed for a little bit before passing out. In other words, the more tired you are, the better you sleep.
Nothing too crazy, so let's make the connection. If the quality of physical rest we get is proportional to how physically tired we are, then perhaps the quality of emotional/mental/spiritual rest we get is proportional to how emotionally/mentally/spiritually tired we are. Peace of mind or contentment is a restful state; therefore it only comes after being sufficiently tired.
For the sake of clarity, I'm going to equate "peace of mind" as a state of spiritual rest —not because there is no mental or emotional quality to it, but precisely because it's both. When we're at peace, we feel mentally relaxed as well as emotionally fulfilled, therefore "spirit" or spirituality is the best way to talk about both mental and emotional well-being at the same time.
If our quality of spiritual rest is proportional to how spiritually tired we are, why do we run away from our worries? They are precisely the thing that will bring about peace! A good night's rest comes after working out, peace of mind comes after spiritual exertion. What is spiritual exertion? Well, it's about making moral decisions, which are always accompanied by worries.
Note: moral decisions is a pleonasm: all decisions are moral, so there's no need to say moral before decisions. To understand this, just think of how you spend your time. If you're doing something, at some level, it's good to do the thing that you're doing. This is an obvious simplification since we run into things we're prefer not to do all the time, but that we do them anyways means that there's an aspect of good to it, whether its pleasurable, to avoid punishment, or otherwise, we may know it's overall bad, but not totally. If something was completely bad, you wouldn't do it. If there was absolutely no pro at all, physically, mentally, emotionally, spiritually, you wouldn't do it, therefore all decisions are based on good and bad evaluations, pros and cons, etc. All decisions are moral decisions, so it's enough to just talk about the decision itself.
Making decisions is hard because some decisions are better than others and it's hard to tell which ones are actually good or bad. To make decisions requires spiritual strength, just as lifting weights requires physical strength —a decision always has the potential to alter the course of your life no matter how small; that is where the fear, anxiety, and worry of making decisions comes from. We try to alleviate these "burdens" because we think it's bad to be strained, but if we thought tiring your muscles while working out was bad, no one would work out. The fear, anxiety, and worry that comes from making decisions is equivalent to working out: making decisions requires spiritual strength, lifting weights requires physical strength.
Most people judge "good" and "bad" on the basis of their feelings. If they feel bad, that is bad, and if they feel good, that is good, but this is flawed because if we applied this to the exercising case, we'd say that exercise (which feels bad when doing it) is bad for you and eating junk food (which feels good while eating it) is good for you. In terms of spirituality, feelings about what is a good or bad decision cannot represent whether our decisions are actually good or bad, only the consequences, the results of our decisions can tell the story.
When we evaluate a decision to be good or bad, we always evaluate it based on its intended goal. If I want to create a company, there are certain decisions that will be good and certain decisions that will be bad based on that goal. If my goal is to have a family, then certain decisions will be good and other ones will be bad, and this goes completely contrary to what may be good or bad for creating a company. The goal defines what is good and bad and the more goals you have, the better at making decisions you'll have to be in order to satisfy all the success conditions for all the goals while avoiding all the failure points. If I want to create a company and have a family and also treat my kids well and make have the company bring in above $1 million in revenue a month, that will require better decision making than if I just want to have a good dinner. The difficulty of decisions scales to your level of want; just like the difficulty of lifting never lessens, you can always try to lift more. Evaluating decisions as good or bad is a life-long endeavor, it has no stopping point.
In the same way people loath going to the gym in order to stay in shape, people loath decision-making since you have to continually do it to train good judgment in decisions. People that stop working out don't stay in shape; people that stop making decisions don't build good judgment. People can learn to like going to the gym; they learn to like straining themselves physically and envisioning a better body. People can also learn to like making decisions; they learn to like straining themselves spiritually (emotionally and mentally), considering different decisions, values, consequences and envisioning a better future (where they are closer to their goals). Each person is rewarded with better strength and good rest in-between workouts.
That's what peace of mind is; it's the rest in between periods of making decisions that affect the course of your own personal life and others. Your actions, no matter how small, have an affect on people that is non-negligible, and to think about and act based on what is good or bad in regards to yourself and others requires strain. The worst part for most people is that you're completely on your own. No one can lift the weights for you, your decisions and whether they are good or bad have to weigh on your own conscious.
It's a mistake to think that youtube videos or articles can help you lift heavier weights or help you make better decisions. At best they can help with form and understanding, point out certain decisions that may be worth looking into, but it can't actually make you stronger; it can't make you better at evaluating between all the different decisions that you could make in a given situation. You have to workout yourself; you have to make your own decisions because over-time what's more important for spiritual strength is knowing how you came to the decision that you came to, and if you delegated the decision to another person, then you haven't learned anything about yourself for future decisions, you've prevented yourself from learning anything because even if you made the right decision based on someone else's advice, if you haven't understood that advice in its entirety, you won't be able to replicate it, you'll always be dependent on advice, but this is exactly what most of us do. We ask for advice, take the flavor which seems most correct, then move on with the situation, never giving a careful consideration to why that advice was the right advice or if it was right in the first place, or if we only feel it was right and not actually right. When you go the Internet for advice, you're asking for other people to lift your weights, and there's plenty of people that are happy to do so, and it won't help you in the long run. What's more important is your decision-making process that grows over-time instead of getting a single decision right, but if you always ask for advice in every decision, then that is your decision-making process, in other words, you have none; you delegate it. To make decisions is spiritual strength, so if you can't make your own decisions, you can't lift anything. Advice is likely preventing you from growing.
So how are you supposed to learn how to make better decisions then? Think about what your goal is and if your decisions help you get closer to that goal, that way you have an honest appraisal of whether you're improving or not. You have to believe in trial and error as well as your own ability to discern what trials are worth trying and which errors are actually errors. Don't look for advice, look for understanding to reach your goals. If you don't have a goal, you need to choose one or figure it out; what decisions will you make to figure out what goal is appropriate? You can still exercise decision-making in attempting to figure out a goal. Some decisions are better for figuring out what goal you should adopt than other decisions; you can't escape the gym, just because you don't have a static goal doesn't mean you're exempt from making decisions. My recommendation is to read classical fiction and pay attention to the characters: their personalities, what decisions they make, and where they end up. Find the connections between these characters and your own decisions as well as other people's decisions; things will start to come into focus.
Realistic narratives are the best way to learn how to make better decisions because they don't pretend that life and making decisions is easy. There are deep conflicts and judgment errors in which decisions are appropriate and which are not; the world is shown as deeply lopsided and to overcome that lopsidedness requires a great deal of effort and insight that characters often don't overcome. There's no clickbait titles on how to be happy, how to change your life, how to stop working out, how to learn the key to all good decisions, how to be fearless, etc. The human wants you have and how to get them cannot be codified into a step by step how-to guide. Advice cannot make you stronger or better. There is no secret to learning how to lift more than you can actually lift. Narratives give a progression of thought, feelings, and experiences that each character has while going through their own spiritual strengthening that may be helpful, but at the end of the day, you're on your own. You're alone for all your decisions.
And that's not a bad thing because after the strain of working out, all the benefits, all the gains you get are also entirely yours. The peace of mind that comes after making hard decisions is yours, no one else's, and it's well earned. Making decisions is painful, but there's no escaping it if you want to live —sometimes it hurts more to be alive than to be dead, just don't stop trying; the rest will be worth it.