Jumpy boost and fuel cut like cut off?

[dvd]

I have a ca18det, fmic, hksbov, nismo fpr, sohc maf blow through setup and a mechanical boost gauge. Recently i've been expereiencing cut offs or boost droping. If i'm on the freeway and holding the pedal WOT, the boost would go up 10psi then slowly drop to 7psi on 4th or 5th gear. Then recently i've been WOTing on 3rd and it would cut off like a fuel cut off. I tried it agan but this time i was lookin at the boost gauge and the boost gauge looked like it was jumping around. The turbo i have is a gt2510, maybe my wastegate acuator is broken? I dont know. Could a vaccum leak cause a cutoff like that at high rpms?