who's in the wrong

I know we shouldn't be together I tell him all the time to leave (even nicely). He wont and I refuse to cause a scene in front of my son. . .anyways, I caught him talking to a girl he had sent dick pics. and even told her he loves her. He wouldn't leave, he's on the lease and my parents wont give him a 30 day notice because they think I'm just over exaggerating I message a guy that I had a dream about him as when i lived in Hawaii he was my best friend the only one I could talk too. It was seriously nothing bad but I got a phone thrown at my head and keys thrown at my thigh that left a huge bruise. who's at fault?

He makes me feel like shit all the time but wont leave. I don't think I can take much more of his verbal abuse and I don't know what else to do. . .I want to leave but I'm watching foster children I'm suppose to be getting paid for from my parents but haven't. I screwed up everything because they needed my help meaning I dropped my lease agreement and job for them.