Conflicted Heart

I've been with my boyfriend for over a year now (since April 2016) BUT I've found myself with the biggest crush on a girl. I really care about him and he's one of the few people who know I'm bisexual. I've told my boyfriend about my feelings for this girl and he's given me breaks so that I could tell her how I feel but each time I get too scared and back out, and after a while the feelings die down. Now I feel stronger for this girl than I feel for my boyfriend but the issue is that she might not even be gay. Sometimes she gives off small signs that she may like me (doing the things I do, holding eye contact) but when I was going to tell her I liked her over the phone all she would talk about was how another girl liked her that was in the closet and how she turn the other girl down. Perhaps she's in the closet and is just like me. Right now, my feelings for her are getting in the way of my relationship with my boyfriend. I really don't know what to do!