I wasn't ready to have sex at 18 and was pushed into it by my boyfriend. The relationship turned bad because he then thought he could push me into doing anything he said. I got out and was only able to have sex again when I confronted some of my own PTSD issues.

I agree with everything that's been said here. It's abusive to have someone try to control you sexually, mentally, physically, spiritually... when you are not willing to conform to what they want. I agree that counseling is a good solution. If she refuses to go to counseling, then maybe it's time to re-evaluate the relationship. Perhaps after some time apart, she would understand that she loves you more than her desire to have sex.