Afraid I may lose a friend?

I am a 16 year old boy and I have recently been having some regret and doubt of my skill because of my inability to seal the deal. There is a girl that I like allot but I never really had the backbone to ask her out, I known her for about two years now and we have been great friends so far, but thats just it were only friends. I always felt as if she didn't notice notice me even though she's giving off vibes that indicated she liked me,This is just the tip of the iceberg with my problems because 5 months ago she started dating one of the star swimmers on the swimming team which bothered me allot as I felt he had stolen her from right under my nose. I showed no signs of my feeling for her and pretended to be happy for them. There relationship only lasted 2 months because her boyfriend was moving to NJ because his dad hand landed a new job, There breakup process was very emotional and I was the first one to to reach out to her when she was in a depressed state after her boyfriend left. Over the course of the next couple months or so, me and her had really been bonding even once sharing a kiss but we were never officially bf & gf. After months of absence, her old boyfriend returned in late April due to family issues. Right now she's single but I can tell it's a struggle for her to decide who and what she wants. We don't talk as much as we used to due to an awkward silence between us, I fear that the complications in our relationship my cause me to lose a friend. Any advice please help.