I have vaginismus and it is putting a huge strain on my relationship?

I have been dating my boyfriend for 4 months, I feel like we are in a rough patch, because of my vaginismus. I have been trying really hard to deal with the pain during sex, but sometimes its just too much and I get really upset. I don't know what to do, we really connect and I don't want to lose him because of what I can't control. Also, my boyfriend insists that it is all in my head, that I just need to relax, but even if I'm drunk or relaxed, its terrible pain. I think I may've dealt with the vaginismus, he can penetrate, but the bottom of the entrance to my vagina feels like its getting ripped when he goes to insert his penis. I don't know whether I have a secondary issue. GRRRR...if anyone has any input on any of the issues, PLEASE HELP!!