new partner , not orgasiming

In my last relationship I had amazing sex with my boyfriend. I would get wet before even having foreplay because I would get such amazing orgasms during intercourse with him (in any position). The past five months i've been seeing someone new. We recently started having intercourse, and it's awful. He is larger then my ex so some positions are uncomfortable, and i can't even seem to get wet. Is there anything i can do to improve this situation? I've tried asking him to do certain things but it's as if i'm concentrating on it now since it's not happening. It's awful going from mind blowing sex, to sex that's not even on the charts :-( . Any ideas are helpful, thanks :-)