Secretly in love for 5 years to my best friend

So... I've never told anyone that I've been in love with this girl for five years now because... I'm also a girl. It all started back in school, I hated her at first because I felt that she was trying to steal all my friends, but then one day when we were alone she opened up to me and talked about all her problems and I saw myself wanting to help her and always be there for her. Three years passed being ok-friends and then we started getting close because we were the only ones in school with year long lasting relationships. Last year, she broke up with hers and encouraged me to break up with mines because he was being a jerk. Then we started getting really close and I've been having to hide the fact that I'm in love with her. We've had sleepovers that I have to hit myself to sleep, I've given her every advice possible with relationships, I've helped her get with other guys, and everything a best friend should do. But recently I've been getting pissed everytime she talks about guys she likes and I'm afraid one day I'll snap on her. I've been being mean to her and her crushes without control. About a week ago, I told her I liked a girl and she was totally cool with it and said that no matter what, we will always be best friends. Thing is, I can't stand looking at her with another guy again and listening to her boy problems because I'm the one who loves her more than anything. I don't know if I should confess to her or not. Our friendship might be ruined forever. She's the closest person I have in this world and I am hers. I don't know what to do. I keep hiding it but I'm breaking down and stressing and we're almost off to college and I don't know what to do. Advice?

I think you should tell her how you feel. It might be risky but that way there might be a chance. If you don't tell her you will never know if you missed out on something that could become truly amazing. Keeping it all in isn't worth the pain. I am bisexual and I started to like one of my friends about a year ago. I told her and it turned out she like me back too. In the end it didn't work out but we are still good friends. It made me feel a lot better to tell her even though I knew I could have been risking our relationship.