How to not zone out when playing?

Hey, so getting straight to the point, I'm not very good at this games and after a recent losing streak I've realized the reason why is likely due to me zoneing out when I play. I find that I lose focus and make dumb mistakes like getting out of position, forgetting how to pull off a combo, accidentally not using an ability, not remembering to take my opponent's abilities into account, etc. I know I shouldn't do these things and tend to recognize them as mistakes but only after I'm dead. If someone could give me adivice on how to focus more and sorta "multi-task" when I play as to remember everything I should be doing and learn from my mistakes I'd really appreciate it.