i dont know what to do anymore

what is wrong with me , this may sound stupid and worthless but im so sick of people walking all over me , what have i ever done wrong to get hurt so much in my life, im 15 years old and i think i might be devolping bi polar disorder, i always put an act on infront of others, when im around my family and friends i act happy and im the most cheerful person ever but when im by myself at night times i cry , sometimes even cry myself to sleeep. i have cut a couple times but not deep enough so thats theres scars, cutting doesnt sooth my pain , my hearts broken into a million pieces, i feel so alone and that no one even cares about how i feel and what i want , i always help others out when they have problems and when i need someone , no – ones ever there, i feel like FACEBOOK is the main thing that makes me alot depresser, if it wasnt for facebook i wouldnt of met all the people that have hurt me in my life,

okay so theres this one guy that i have had a thing with for about 5-6 months , the first time i ever saw him on skype, i instantly fell for him, the first time we skyped was late december 2012 we skyped for hours and he was the most perfectest boy i had ever met , he was so respectful and sweet and he just brought a smile back to my face anyways we continued talking and talking and just grew closer he told me he liked me and that was the happiest day of my life, i told him i likd him back and from that we grew so close. THEN in mid april 2013 we started drifting , i would ask if he wanted to see me and he would say cant , busy , family problems , and i was like thats okay if you have family problems im here if you need me, then he started to stop replying , and i thought to myself what have i done ? i thought we had something? i thought he liiked me ? what is happening? i tried messaging him and all that would happen was fighting , alll the time, WE JUST BASICALLY GREW SO FAR APART THAT HE DOESNT EVEN ACTLIKE THE SAME PERSON AROUND ME ANYMORE. WHEN HE INBOXES ME IT WILL BE LIKE “HI.” AND NOT LIKE HOW IT USED TO ME “HEEYY BEAUTIFUL XX ” I JUST MISS THE OLD US SO MUCH.,
ANYWAYS LASTNIGHT I FOUND OUT THAT HE FUCKED A GIRL AT A PARK AT THE START OF APRIL AND THAT EXPLAINED IT ALL TO ME , THATS WHY WE GREW APART HE BETRAYED MY TRUST HE CHEATED ON ME , I WILL NEVER FORGIVE MYSELF EVER FOR FALLING FOR HIS BULLSHIT,
I STILL LIKE HIM ALOT THOUGH I JUST NEED TO MOVE ON AND FIND SOMEONE ELSE I GUESS IT WILL BE HARD BUT I NEED TO TRY . I NEED A BUDDY TO TALK TO SOMEONE WHO GETS WHAT IM GOING THROUGH SOMEONE WHOS ME.