Im no radiant pro but i started performing amazingly in my games after doing 1 thing

All you got to do it just relax and dont get mad

What i do before getting into a game of comp is just do 3-4 minutes of aim training and then i lie on the floor and relax for a minute or 2 and that just gives me the ability to hyper focus on the game. Might not work for everyone but staying relaxed really helps in anything. And if you feel mad trick your brain into feeling calm by saying something like " I am calm and collected" Boosts your mental health in general aswell.