bad sex with long term boyfriend.

So.... my boyfriend and I never have sex. It's just not that great for me. I've had sex before him and I'm his first. We've been dating for 4 years and it's still the same as it's always been. He cums quick and loves it and I swear I fake it most of the time. What should I do?! Is it a mental thing? Should I switch it up? He has a smaller penis and I that's kinda the issue. I can barely feel him sometimes and it won't stay in in some positions. HELP. I want to have great sex with him.