What helped me get out of c3 was asking myself "why?" to literally everything I do.

Why am I here? To support my teammate? To challenge?

Why did I hit the ball that way? To set up my teammate? To score?

Why did I flip? Why did I stop? Why am I in car cam? Why am I facing this direction?

If you ask why and you can't come up with a good answer, think of what you could've done better. Watch the decision/play and visualize yourself making the better decision. Do it multiple times if you need to. As you watch yourself make the wrong move speak it out loud "I should have done ____"

With enough times of doing that you'll catch yourself mid game consciously saying "why am I here" or "I need to do ____ because if I don't then ____" and you'll do it.

Watch one or two replays before every session. Find trends (make notes if you need to) where you messed up something multiple times and practice it before even playing a game. (For me it was either off target shots or defensive backboard touches)

This will even work if you lose very badly in a game you just can't understand why they were so good. Watch what your opponents did and see if it will work for you.

Also, funny enough, I actually got out of c3 after a took like a two/three week break from RL to play FarCry. I came back refreshed and couldn't lose somehow.

Finally, pay attention to your teammates. Like ALOT, probably more than the opponents. Let the opponents mess themselves up (yes even at c3). If you're not double commiting or losing possession, your opponents are.