Should I take him back?

I met my ex back in December. Quick background of me and him, I’m 20 he’s 27, I just graduated from nursing school and I’m inexperienced when it comes to dating and sex (virgin and still am). He’s a veteran, works at a warehouse and has a 10 y/o son. From the start it’s been a bumpy road... we would fight all the time and always making me feel it’s my fault even though I know it wasn’t and he would say it isn’t, we both were busy but he would make an effort to call me each day, and sorry if this is TMI but every time we made up it leads to phone sex. Around February, he distance himself and begin seeing some other girl. I notice him and told him I’m done. So it made it official with that girl. Shortly afterwards, he would call me drunk and upset I would give in. Yeah .... I know. I wanted to tell the girl so bad but everyone said don’t. I mean they didn’t even last a month. Then he would post depressing selfies himself saying he wants to drink, and then some new girl. As in now, that post of girl is gone and he’s asking me back. I just wanna throw it out there because I’m thinking he gets intimidated with me... I seen his ex girlfriends and his baby mama.... it just seems he isn’t used to a girl like me. I can’t comment. So should I let him go or ...?