You can follow nikolgiorgos advice. Actually just because you spend more money in the game doesn't mean you will get better, you might risk getting opponents with stronger teams because the game is trying to balance the teams as much as possible.

Let's say if your team is 7 stars, you actually might end up with teams who are 7 or 8 stars, especially in competitions like CUP or even Champions League so having a stronger team might lead on you on the exactly same path and find yourself in the same situation.