In love with best friend with no chance.

So I have been a tom-boy all my life and in middle school I started to notice I was being attracted to girls. Long story short I've just accepted that I was bi within the past 2 years. Anyway I moved to a new state last year and shortly after I moved I met my now best friend. She started a my job where I was a manager. At first it was nothing just work. Then we would start talking after work before we went home. It started with like 20 minutes and continued to the point we were talking for 3 hours and then talk on the phone and meet and go out. To make this short I will give you the facts. She was unhappy married. She has just now got divorced. She has dated girls before getting married.
I don't know when it happened but somewhere I fell in love with her. I think about her and her day and night. I can't sleep. When she cries it literally hurts me in my chest. But she has feelings for some guy that fucked her and left her and only used her as a booty call. Since she has started hooking up with him she started lying to me and that is one thing I can't stand. I do everything for her from helping with money to helping with the kids. I get off work at 2am and to her house by 6am to wakeher and the girls for school so they aren't late. I do everything she ever wants from a guy but she still makes it very clear she wants "dick" as she says. I have recently tried to get over her or at least push my feelings away but every time I try it hurts so much. Also when I try to date she starts to act weird. She tries to go thru my phone and she gets kind of pissy when I'm texting or talking on the phone. I love her so much but she will never love me the way I love her. I am going crazy and I don't know how to stop this. Please help I never delt with this before because I never felt this way.
thanks