advice needed...

I've been with my boyfriend for awhile and decided I'm ready to have sex with him. I'm very thin and have small hips so I'm extremely tight. I've never let him finger me bc when he tries it hurts like hell. I have seen his penis and it is extremely big. I'm terrified to have sex bc of how much I think it's going to hurt, and I don't think he likes the idea of using lube. Help!