Struggling hard

I never had any good experiences with sex. So now that I want to, I have difficulty staying wet I guess? I'm good to go at first and then we get further in to our stuff and i dry up immediately? I want to try to just use lube because yknow sex dry hurts like nothing else, but my boyfriend has suggested once or twice maybe i should see a psychologist since it seems it's a mental block. But i also just want to know if other women have this dry problm and give me suggestions? I'm 18 and totally inexperienced with most of my own body. But i know what turns me on and I dont underatand how I can just not be the second he gets naked.