Best friend dated the girl i am in love with

So there is this girl i am in love with. Not a crush, a lot mor than that. So life's going normally for me and boom i hear news that she likes my best friend. So what it's just a rumor...and I look at my best friend and he looks so stupid and clueless so i'm like F*ck it. Biiig mistake. My life is colapsing now. She went out with him. That moron doesn't know the luck he has. I can even live normaly anymore. I think of her 24/7. Grades falling, and every single day it pains me so much. I just want to end my life, but somehow that inch of hope still hangs. And even though It's been soo hard to accept it, she doesnt like me. At all. normally sure i would forget, but no. We have many classes together and i look at her every chance i get. It tears me up so badly inside knowing this is happening. I'm going crazy. I need advice so badly. Please people help me.

11, but please dont say i'm too young to love. I've been into so much deprssion in this girl. I've even tried forgetting her but it just doesnt work.

Omfg that helps so much THANK YOU!!!!