wanna wait for marriage but dont know if I can

My boyfriend and I both wanna wait for marriage but both of us are really, really tempted most of the time and both dont know if we can wait that long. We've talked about it a lot, we do wanna wait, but it seems really hard. I'm scared I wont be able to help myself one day and he wont either, and we do it. Does anyone else have this problem? How do I overcome this because ughhhh