Should I break my promise of abstinence and have sex?

I'm almost 21, and a virgin. I come from a mildly religious family, and at 18 made a promise of abstinence to my parents.I have since met someone and been in a strong relationship for eight months. From the start of our relationship I've said that I wanted to wait, and he is very supportive of that decision. I know that we love each other very much and feel that we are soul mates. We've talked about giving in, but each time I've said no because I would feel guilty. It would hurt my parents, although I'm sure they would understand, and I don't know if I could live with that guilt. But should I be holding off on something I want and am ready for, just for that reason?