I win Cup matches , but i started lose league matches. Help for formation !

[Stealthie]

I think 3-4-1-2 is better, but you have to use AMC. So try to buy AMC.
Since you have 1 player injured, try to buy more players to have them as reserve. I have had 4 players injured for 2-6 days. Thus, the reserve players can substitute the injured ones. You will need them when you in your future progresses and also try to upgrade your sprinklers, it will lower the probability of injuries at home matches.

In my opinion the blue arrows are not needed for defenders, otherwise they only defend and don't go forward when you have the ballpossession. In my matches my defenders also do score sometimes.