What!?!

Okay so my boyfriend and I have been trying to have sex. I'm a virgin. We've tried a few times but I always get this pain at the back of my vagina.

He's pretty big but I figured vaginas are meant to stretch and take it in....

Today we got further than before but when he thrust, it hurt pretty badly - even though his penis was barely in.

Turns out I bled a bit. I think that the back/bottom part of my vagina tore a bit.

Is this okay?? How do I fix this?

Is it even possible for a vagina to be too small??

Please help! I feel so horrible about this!! :''(