What exactly do you mean by "he doesn't fit"? Do you mean that his penis is so big that it hurts when he enters you? A vagina is meant to be able to stretch, not just for having intercourse, but for delivering babies as well, and in my experience, i've never seen a 9lb penis before, so I think this is probably just a matter of 'practice makes perfect'. I know that's probably not what you want to hear, but it does get easier to receive a man after having sex with him at least once. Especially if you are a virgin. You might just need to relax a bit more, if you're tense 'down there' then it definitely makes it alot harder because the muscles in your vagina tighten and the probable cause of that in your case is the fact that you are a virgin and anticipating the feeling of your man entering you could be causing you to feel nervous, thus causing you to be tense, thus causing the muscles in your vagina to tighten.

Also...You can train your vaginal muscles to relax...Try this...Insert 1 or 2 fingers and cough. Feel it loosen? Well now try to loosen it without coughing, and keep practicing that until you can do it on command without fingers involved. This should make it easier for you.

sometimes the older you are when you get married and are a virgin, it is extra tight... My Dr. Told me that you can get some dialation rings from your obgyn and actually help stretch out your opening. I was only 20 when I got married and was a virgin and that hurt like hell as it was... My sister was almost 30 and had two months of pain... Try a good lubrication as well... And make sure he's getting you ready too... Relax... Have him love on you (not intercourse) and get your body wanting it and liking it more... We women take a lot longer to get ready sometimes.
Good luck... It can be painful. Don't be afraid to go to your gyn and ask for help... They've heard it all before and more!