What do i do now i love her?

So yes, i am a girl and i love a girl I have known her from year 8 and i am going into my 2nd year of college so about 5-6years We got together in year 9 and stayed together for 3-4months but she left me =[ I broke down and could not think of anything but her!! I cried every night for her she was my EVERYTHING!! After about 6months she asked me back ..just like that I of course said yes i could not resiste her But she started to blank me and we seemed apart and i left her 4-5months after It really upset me but she treated me like a friend not a girlfriend But i have never stopped loving her Should i tell her how i feel or will it kill our friendship ???