How to overcome pain before ?

Ok, so basically my girlfriend and i are majorly in love and after 2 years together, we want to make love. Small problem. Whenever we get to it, as I push in, she writhes in pain. We practice a lot of before and all that. But because of the pain, I've never actually broken her hymen. What's the best was to get past this. She's never been more ready so I know she's not resisting it.