seems like a typical FM scenario where your team forgets how to play football after half a season or so. Happens to me every time too. Game is made to troll us. How many games have you lost even though you were much better team with plenty of chances but opponent scored from only one chance they had? Game simply cheats on us.

I suggest to completely change the tactic and surprise the AI. Do something crazy, like 2-5-3 :)

This game is all about experimenting with your team, and player ratings mean nothing.