Coming back after a 2 week ban - what (and how) now?

I'm not a good player and I am not a good teammate. I didn't get ban for straight rage or offensive language but for passive-aggressive shit talk and expressive my inner giving up which, I believe, annoyed and demotivated my teammates. I tried muting all and I tried focusing on myself. At this point I think that I am so weak mentally that the slightest negative thing can break my spirit totally and my attitude and play collapse.

I am afraid of playing. I've been staring at the client for the past few hours. I am not sure if I can handle it anymore. And I don't want to uninstall - there are moments when I still have authentic fun.

I realize there is no one simple trick or tip to change because one does not simply change his personality and mentality. But I want to know how people manage to reform, to change and to work on yourself. How to approach this process?

Thank you. random shit player.