This jackass keeps throwing me down

So about 3 days ago my boyfriend broke up with me, even though it wasn't the greatest relationship i put $100 percent into it. When we meet he knew I had kids that I was a single mom that was struggling. He broke up with his girlfriend at the time and started talking to me saying she didn't give him attention that had been together for 8 yrs. we talked for a while and decided to date, he treated my kids nice he treated me nice but then like 3 months into it he started treating me like shit, I worked my butt off to pay all my bills and give him money because he had gotten fired, he took me grocery shopping and took me wherever I needed to go. Sex wasn't the best it sucked , small dick, came early and never made me have an orgasms if I wasn't the one to do it but I never said anything cause the first time I expressed what I felt he got mad, after that he always got mad, so anyways about two weeks ago he started being a complete dick and 3 days ago he hit my kids and I told him to leave he then decided it was over and that i should talk to him no more so he left , the next morning he came knocking on my door saying he had gone back with his ex who satisfied him, after all the bad shit he had said about her. He keeps texting me blowing up my phone putting me down I have anxiety and depression and I've been a crying mess, he screws me over emotionally and he took my money yet he istnt the problem according to him I am, the phone bill I pay but it's under his name and I can't give up my phone cause I just payed my bill and got no money, I'm so torn apart from how a person can be so cruel and heartless using women to however they want. I know it's my fault for letting him into my life but now how do I get back on my feet how do I stop my depression from eating me alive