Boy problems, what should I do?

Im 13 and in 7th grade....Ok so this is a reall long story.

First there is this girl at school that I'll call K and i have two best friends: S and B. then i had a boyfriend:M.

Well one day during lunch a whole bunch of people were in the gym. Me and 5 my friends were playing basketball for fun( im a cheerleader). M(my boyfriend) is the only one sitting on the bleachers. All of a sudden, K runs across the gym to him and starts saying stuff to him. She was laughing hysterically and M was looking at her dumbfounded. Then K ran over to me and was like y do u go out with him he doesnt even like you and he has something to tell you. K led me to him and told him to tell me what he has to tell me. He said he didnt have to tell me anything and that K was just talking about me behind my back. After lunch, a couple of people told me that M and K were talking about me and how im ugly and questioning why M shud b my boyfriend, etc.. SO I ignored him and K for the rest of the day. He tried to get my attention, but i kept ignorin him and in 7th period i kept ignorin him (and i sit next to him). After school, he sent me a text saying "im breaking up with you because too much is going on right now". I was heart broken, and didnt reply. Everyone was telling me how that was so wrong of him to do it over a text and how he did me wrong. The next day, he wasnt at school but he texted me in 3rd period and he asked me if i was happy that people aren't talkin about me anymore because everyone talked about me when we went out. I said idc about those ppl i jus care about him...then he said that hes gonna b at school later. He didnt come to school but after school he textd me and asked if i was ok and i said no then yes then he said that he heard that i cried wen i broke up with him and he feels bad but he heard that i said that i wud never go back out with him so hes not gonna ask me out again. i told him i was just lying because people were trying to persuade me to think of him as a bad person. then he asked me out again and i said yes...smh. i asked him y he broke up with me and he said because he "lost his mind and it was a mistake". evry1 else said it's bcuz someone told him to and he listened. Then he txtd me "ily" and I said "ily2" and he said im tired of going out with people and im not braking up with you but if i do its because you didnt do anything wrong. i sed so your going to brake up with me later for no reason. he said it'll b because im tired of going wit ppl. and then he asked if we could take a break after v day and then go back out later. i said ok but i was really madd inside. i began questioning his feelings for me and the next day at school he was totally ignoring me and having his arms around other girls!! i was certain i had to break up with him. in 3rd period i texted him. "i dont want to go out with u anymore, and im txtng u this so u can no how i felt." i didnt get any reply. the next day was valentines day and i was feelin really badd for breaking up with him. he showed everyone the picture of what he was going to get me for v day. It was a bigg teddy beear with a basket full of cookies and lots of candy. i felt so stupid for breaking up with him. after school after cheerleading practice, S txtd me, this is how it went.

"Can i ask u a question?"

"Yea"

Do you still like M?

Yea y

cuz he jus asked me out what do you want me to say

NOO I STILL LIKE HIM

ok i said it

thx

yw

Then, B txtd me an hour later:

"Would you be mad if S went out with M?"

yes

y

because i still like him and we just broke up yesterday

but he did so much wrong to you and he broke up with you under command

I didnt reply to her. Then the next day S was hiding from me, but people around me kept saying things like r u okay and i cant believe she did that. At lunch in the gym i pulled her to the side and said "u didnt tell me what you answeres M yesterday" she said "i told you i was gonna say yes". I WAS SO MAD, BUT I FORGAVE HER. M was still ignoring me, but i always hang around B and S and M always comes over to hug or tap S's butt. it kills me inside, and I really want to confront S and tell her how shady that was. they've been going out for a week and M recently became my friend again two days ago. i really want to STEAL him from her, but i'm not sure if he still likes me. B thinks that wat S did was fake as well but she said i shud let it go and get another bf. Im thinking about doing that. For now i just suffer as i watch them flirt and do STUFF right in front of me. S thinks im all better now. Someone pleade help what should I do? Should i get another boyfriend? I also keep listening to Cher Lloyd - Want U Back!! MY HEARTS MELTING INSIDE OF ME I MADE A BIG MISTAKE BY BREAKING UP WITH HIM.