How do you defend in this game? Div 6

First of all, i cannot believe i'm asking this. It is genuinely a cry for help.

I suddenly dropped from div5 promotional match to div 4 down to fighting to stay up in div 6. It just felt like the game got sweatier.

People in div 5 make stupendous skills, run around my keepers, shoot from 80 yards out, know exactly where the ball is going etc while i find to hard to defend.

I have turned off crossplay. I play really slow, i do not sprint. I even stopped holding L2 when moving my players so i'd follow the ball, i.e. when defending, but still.

I could be winning 3-0 and from 70th mins it'd be like i'm playing a different person. I'm frustrated.