I grew up a very angry teen, lots of rage and with my ocd i was so confused and lost. Now it is possible my methods wont work as fast for others as it did for me, i am an infp and i always held my anger and emotions inside of me never letting them out, so i know a thing or two about holding things in. Anyways let me share how i was able to control my anger and become a pretty zen and chill person, and holding anger in is only one part of controlling it, hold it in, breathe, and release. 1. Meditation- this is the most important thing you can do for yourself i believe, meditation has countless benefits and it actually psychically changes your brain, https://www.forbes.com/sites/aliceg...n-can-actually-change-the-brain/#1fc2fa201465. 2. realize things are not worth it- when you get angry i want you to stop for a moment, ask yourself why am i angry?, is this anger productive or is it destructive?, until you change your mindset and strive to become chill you never will. A good example is road rage, my mom will go into a rage when someone at the store pulls out infront of her, she screams and gives me a headache, this is is no way productive and you are not in control when you do that, instead take a deep breathe and say this is ok, i will leave eventually so i will not get angry at that person, instead let me spend this extra couple seconds being appreciative of what i have and do some meditation while you are at, instead of viewing situations as negative take them as they come and be appreciative of the things you have or the things around you, and do not let a tiny thing mess your chill up. 3. forgiveness- how can you control your anger if you never forgive, does that memory of a bully anger you?, forgive them and except what happened, when you do that you will be at peace with them and yourself, also learn to forgive yourself, learn to love yourself, stop being such a negative person because negativity breeds anger and hatred, always look at the positive things and dont dwell on the negative. 4. strive to become chill- i am a laid back person always have been, but i used to be a very crazy person, so i strived to become chill, i wanted to be like those old martial artists you see who seem to have all the answers and nothing gets to them, so i strove for that, if you actively seek chillness than you will slowly find it and how to be it, learn to harness that anger and use it for yourself, dont just try holding it in and letting it fester, breathe, and release. And listen guys, i know the title says full mastery but even i get anger sometimes, anger so bad that i dont want to stop because it feels so raw and powerful, its especially during times like that, that you need to calm down and breathe, i very rarely get like that tho so i dont have many opportunities to try mastering high levels like that.