Can I fall back in love with my boyfriend? Because I really want to...?

Well you don't say what he did that was so wrong. So it's hard to answer, but in the end if you have doubts there are reasons to it, you can't just "make" yourself fall in love with someone. You either do or you don't, if you don't you need to tell regardless of how he feels about you, you can't be with someone just because you don't want to hurt their feelings, because you'll be the one ending up getting hurt. If he did something stupid, he did something stupid, he has to pay the price for it. Most women leave their partners for going to jail, because apparently whatever he did was more important than being with you.