you should try 4-2-3-1 and its variations I think (the 3CAM version or the one with 2 CDM), Falcao up front and Mata-Rooney-DiMaria behind him. RvP should be sold (yes, sold) because he's getting older and you can get 30m pounds from him, which is great if you decide to sign Falcao permanently.
This is what I think :
DDG
Shaw-Smalling-Jones-Rafael
Blind-Fellaini (both CDM)(or play Herrera-Fellaini in CM)
Mata-Rooney-DiMaria (All of them are CAM) (or Januzaj-Rooney-Di Maria if you want to play wingers)
Falcao
just a transfer suggestions :
1) buy a versatile full back (who can play RB/LB) (ex : Clyne, Toljan) or a RB only is okay
2) buy a player who can play CM/CDM (ex : Pogba (oh, we really miss you, Paul !), Lucas Romero)
3) buy someone who can play AM (R/L/C)(ex : Oscar,Shaarawy)
4) Sell RvP and Young (sell Young if you don't play with wingers)
Hope it helps