What to do between love and preferance

I have grown up with one of my best friends since as long as I could remember…and we have grown wrather close…she is just as old as I am and she loves me and I love her. the only thing is that as I have grown and matured I’ve descuvered that im not straight im gay…as shy and as emmbarresed as I am to share this on the internet I am despret. I have tried numerous times to tell my girl friend the truth…but due to certain occurences in her life she needs me on a serious level. the very last time I tried to break up as some people would say, she had gone through with triing to kill herself. just because im gay dosnt meen I dont love her. I would never let myself be the reason she would kill herself…I love her in the way that shes my best friend…and im happy with her…but in the way we are sapposed to be more than friends..im not interested…and I also dont want to loose her..im very lost in the situation…I need serious help…I just want some different views on the situation…preferably on what to do…