I haven't been happy for so long, but there is this girl and I knew she had a boyfriend and loved him and he's a great guy and he's my friend now, but I still fell in love with her. She was the first person that made me feel happy in so long even for just brief moments. We ended up talking about how we used to both like each other, but neither of us knew. We have slept together twice now(one night right after the other) she initiated it the first time and I did it the second. It's been weeks now, and she pretends like it didn't happen, although I've never brought it up with her. She never told her boyfriend, and we just keep going as we were. I really do feel awful for doing that to her boyfriend, because he really is a good person. It hurts like hell to see her love somebody else. I never knew that I could love somebody this much, but I can't tell her I love her because she's happy. I also can't avoid her and stop being friends with her because we are in the same classes, she was one of my best friends before I fell in love with her, and have the same friends, but every time I think about her and how I can't love her I just want to hurt myself again. I need to stop loving her, but it feels impossible because I love her so much that it hurts. What should I do??
PS: I'm a girl