Emotional Suicide or Sacrifice?

[The Lonely Shaman]

I've been thinking for a while now, for the past 4 years I've had this amazing friend who I've looked after through thick and thin, whenever she needed me I've always been there, I've held her in my arms while she cried and comforted her, I've held her because she couldn't sleep due to anxiety and she just drifted away in my arms. I'm not afraid to admit i love her; but she only thinks of me as the older brother :/ (I'm not by the way but you know how some friendships turn out). Recently she's been happier than normal; but she's drifted away from me and i cant help but feel it was me that was making her upset, not to mention i think she fancies my mate which doesn't make things any easier on me, I've always put her first no matter what and in most case it was my emotions that had to be put on the sidelines.
I'm starting to think someone/thing is punishing me for something I've done in the past but I always tried to make up for them, I don't want to have to put my feelings on the sideline any more but i don't want to lose her, i can't, recently she's been the only thing keeping me alive (honestly no joke), do i sacrifice my feelings once more for the sake of our friendship or do i lose her and try to find that illusive silver lining. I've always had things i would happily die for but this is the first time I've had worth living for.