"have a look at my team and feel my dissapointment!"

These words are in what you are wrong. I too had a "era" as a token buyer, and the players are not simply a collection of stars, there's more than that.
This game is not; if I have +0,1 general Q. than the other team I win. Every player have a form to play and perfectly a 4* can contribute and affect the result of a match more than a 7* or 8* player. Remembert that thats a game and all are internal proggramming and % of effectiveness and so.
I've seen after 26 seasons teams like your and I'm not surprised.
As a manager I will suggest you to start doing a little change of mentality and see the the truth of your players, take a look at how they contribute in the matches, and no the stars.
Too I know I say this words usually, but I will say again. 1 player, can give you the 2/3 of a league title. So maybe you need this leader in the MCs or ST's line.

I will add that 1 star are only 5Q. of differance and that will never be enough or a guarantee of your victory...

If you want you can post a pic of how goals, assistances have, matches played and ratings have your team. That will help other managers to suggest you better than looking a collection of stars (almost me)