Same situation for me, man. However, I had a difficult twist to deal with.
My senior year in high school I began to feel the pressure of my sexual orientation (bisexual) and fell in love with my best friend of the same gender. I couldn't bring myself to tell him because I didn't want to lose him as a friend. We ended up being roommates together at university, so I told him and he said he had no homosexual desires at all. I was absolutely devastated because of the incredible desires I had for him.
As someone previously mentioned, someone you love should be (and most likely is) someone you share interests with and can connect with other than just sexually. We definitely connected to each other more deeply than either of us had felt before, so it was a real difficult thing for us both. I (admittedly) badgered him for nearly five months about it. About one month into our second semester, we had a sexual experience (I think it was because we were both so horny), and this lead him to see if a homosexual relationship would be right for him. Very noble of him, I admit.
It's been nearly three years, and we are still in a "relationship." I wouldn't call it a full relationship, simply because he still says he is heterosexual. He has told me he is bisexual at least emotionally, but not physically. So, we are almost in a more tangled web than before, but we are practically already partners as far as an emotional relationship goes. We spend nearly all of our time together and we share so much of our lives with each other. It has been very difficult, and I have times with I wish none of it ever happened.
You'll have to gauge the situation yourself. If you see these desires as damaging, try to find ways of spending time with others and get your mind off of her. The following song by Sarah McLachlan sums up both our situations pretty well, I think. Take care, and I hope things work out well in the end.
"Stupid" by Sarah McLachlan
lyrics
audio [4.6 MB]