Done it too many times but it still doesn’t go in..

Yas

Guys please help me, me and my boyfriend have tried to have sex so many times now. We’re both 18 and he’s the first guy I’ve tried sex with. I don’t know if his is too big or if my hole is too small but it just doesn’t go in I’m so confused? We’ve tried it a couple times now but only the tip goes in and it hurts like hell. Please help a sis out :(