Here is what I understand. I have no expertise, I have long studied and learned to apply these ideas, after trying the willpower approach for much of my life. Most of all, I encourage you to read what experts say; it's fundamental psychology (even if I denied it for a long time).

I have plenty of flaws but I am blessed with willpower, at a level that drives others crazy; I am always pushing the furthest, always the last to give up. Perhaps that's been built up because I used willpower to solve my problems most of my life; perhaps I used it because it was already a strength. I also used it for my emotions, as if they were an injured knee and I just had to tough it out and would run anyway. In hindsight, I was ignorant. I'm not sure if the following is what you seek, but feel free to ask questions and I'll try my best to answer.

Imagine there is a First Law of Emotional Dynamics, the Law of Preservation of Emotions. You cannot destroy them; you can transform them from one form to another (e.g., fear becomes anger). If you don't process them, they remain, sometimes lifelong (trauma, PTSD). Emotions are going to be there and they are going to have their say. If you try to suppress them, they will have their say without your input or consent. You will deal with them, in an unhealthy way (drinking and drugs are popular!) or in a healthy way. Your choice! The most practical tip I have is, replace unhealthy coping with healthy coping - the drive is genuine and normal; you just need a healthy way to take care of it.

Second Law: Input of emotions is from specific sources, internal and external. Output is by default toward the easiest target. Your boss screams at you, you supress your anger/fear/shame, you go home and find yourself yelling at whoever because they didn't turn off the light - a lot safer to yell at them than at your boss! Much more consequential and also typical: A child feels angry at their parents; the child can't express anger because their parents don't allow it, implicitly or otherwise; the child can't even blame the parents internally because a child is so dependent - for survival - on their parents and trusts whatever they say or imply - 'it can't be their fault'. So the child turns the anger inwardly, toward themselves, and feels shame (anger becomes shame, see the First Law). As they get older, their shame (an incredibly damaging emotion) becomes anger - they hate it - but they still don't turn it at their parents; they probably don't even realize the source. The anger is aimed at easiest targets around them, maybe their own children.

Third Law: Emotional energy is intangible, immeasurable, and indefinable, but it is real and it is limited. You have a limited capacity of emotional energy. I used to insist this was nonsense and that through willpower I would just keep going, and what was going to stop me? It was sort of like insisting that I was going to sprint a marathon. I can insist and have all the willpower I like but my body doesn't have the capacity and neither do our emotions. If you push past your capacity, there will be a rebound effect - I did this all the time, completely disregarding my emotions as a matter of course, and then I couldn't understand why, subsequently, I couldn't seem to function - 'I just need more willpower!'. You can imagine how that worked out. Now, I manage that capacity - I do things that build it up, I spend it selectively, I anticipate my limits, which I have learned about. Sometimes I do have to push myself beyond them, through willpower - if a loved one is seriously ill, then that is more important - but I am making a choice, I have built up my capacity over the years, and I plan for and manage the rebound in a healthy way.

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But notice that I described my early perspective of emotion as like an injury, as if it's a malfunction or friction in the gears. More than anything else, it is you; it's the core of you, it's your actual experience of the world and your life, and it's also essential to judgment, instinct, intuition, etc. My early perspective was 180 degrees wrong: Have compassion for it, care for it, love it, it's important, it is your humanity. That change in perspective has transformed my experience of life, my ability to love, my perception and experience of the world, and also my instinct and intuition.