Im in love with him but he has a gf.

Title says it all. A few months ago I met literally the most perfect man. The moment we met, I just knew he was right for me it was crazy. We were talking for hours and this one person joins our conversation, and she starts telling me about his girlfriend and I was thinking to myself how unfortunate that is for me. But anyways, this was when I first met him, so I was fine on being just friends. But him and I spend at least one day a week together and it's just so perfect. I feel truly safe and secure with him and ive opened up to him about things that I didn't think I'd ever share with anyone. I always make sure to talk about his girlfriend and just constantly bring her up when I see that him and I are getting too close just because I would never want to get in the way of their relationship. And a guy as great as him I'm sure he'd have a wonderful gf, so I really wouldn't want to take that away from her. (They're long distance). Anyways, recently he told me he has feelings for me and I of course said that I do too but we have to be just friends. And he replied with "damn". Now, I just simply don't know what to do. I know he's not trying to use me or anything and I do believe we have feelings for each other but should I just drop the friendship? Either his feelings aren't as strong as mine or he breaks up with his girlfriend to be with me. I feel like those are the only two options. Am I wrong? Could I continue to be his friend?