I need relationship help 😭

Well this is my first time posting I just hope to get some positive help well it's Kind of a long story but .... 
Well I am a junior in high school And I've talked to the same boy since my freshman year when he was a junior and when I say I've been done wrong I mean it throughout our three years we've been on and off but every time we broke up he would be the One breaking up with me he would have a girl the next day he would date his ex's and lots more but in some way he would always come back it never fail And i guess you could say I was stupid enough to take him back.... Anyways my mother loves him he came over every weekend and went out with us etc but after homecoming last year that all ended she doesn't like him it's for a good reason basically he asked me to homecoming and al I can say is when we got there he had another date and I was left to dance alone I had to find my friends etc then he lied to her and told her I left him the thing is after that bad situation a few months passed and he HMU I ended up forgiving and once again that cycle of on and off dating began so recently he went off to college and a week ago came home to visit his fam he lives down the street so he texted me and we walked a roughy the block a few times we talked and he told me how he wanted me back but he said "Lets take things slow" to me that made it seem like he had someone else but anyway a few days ago his ex posted a pic of him saying my love my smile etc and I was like wow again remind you he hadn't HMU in like a few days suddenly he HMU like don't be mad we tried to work on us again but it didn't work so will you be my girl again I went off I was absolutely livid so he went on to explain how he knows he was wrong but he's trying.... Skip ahead a few hours i see him and his cousin at this store and he's trying to tak to me but I'm giving him the cold shoulder later that night he's telling me I want you to be happy with me and it would hurt me to much to see you with someone else be my girl again I'm sorry I'll change but I don't feel like he will I've had to see him with plenty of girls he's told me about relationships and al and I always had to deal with it he's hurt me so much that I can't say wether or not he's being genuine he's apologies for it al but he's done it b4 and they say mistakes made more than once are a choice idk y I always let him back if maybe Bc I loved him maybe Bc I felt sorry for him maybe Bc  whwn wewere together it was great and everything felt right maybe Bc he knew exactly how to play my emotions in his favor but every time I think back when he would break up with me and come back he would always make it seem like it were my fault he made me change myself and then said I was wrong for listening 
What should I do please help 😭😩
Ps. Sorry for rambling on