You must note that a change of formation won't work you'll keep having same problems even if you use the 'ultimate' formation. I always like quoting pep guardiola "tactics and formations don't win titles, players do" you must watch out for players that are not performing and remove them even if they are 7stars, every player has a hidden programing that determines how much they perform so if your player is bad he will remain bad even if you train him to 7stars, you can search the forum for more tips on this. I'll recommend that you always buy the assistant manager recommended players they've never let me down