Sex ? .

Me and my boyfriend had sex. I'm not a virgin anymore because his dick did go inside me . But, when he was trying to put it in,it was difficult. He's really big and being a virgin just made it harder for the both of us. He didn't put his whole dick inside me because not all of it fit. He's not really long, He's just really thick. What do we do ? I wanna say its cause i was a virgin but ,i heard there's really no such thing as being "tight" or " loose" because a vagina is a vagina and hell if it could push out a baby why wouldn't a dick go in lol. Could lube help ? Anything ?