Im in Middle School and am suffering from heart ache?

ok so me and the boy of my dreams broke up and now my best friend is going out with him and shes bending over for him to slap her and shes kissing him all the time so he wont dump her and its rly making me depressed because every time i see them in the hallway i want to fall and cry and i always dream about him....plz plz help me find a way to get over him and move on because i am suffering from a bad heartache and have no one to help me through it