Why does my ex think I'm a terrible person?

[733]

I was with him for almost 2 years. We practically lived together, and when he voluntarily left his job, he fell behind on payments. I paid all of his rent, his truck payment, and his phone bill, etc. He lost the apartment (more than one) and his truck because I couldn't keep handing him money even though I lost over 4 grand at that point. I'd always be there for him, I did everything for him. And even after he started working, I was still driving everywhere and paying for everything. I found out during the time I was paying for his things, he was talking to tons of girls on Facebook and asked to meet up with some for sex.

Yes, I was pissed and told people he took my money and cheated on me. But that's what happened. Maybe it wasn't right to talk about him, but he caused it. He blames me for our relationship failing, even though I never hated him for what he did because I know he's not perfect. I stuck with him trying to work it out, and he'd still get mad at me for every little thing. He won't even pay me back because he blames me for making his PTSD "worse" and since he was on the phone with me during work one day, he got suspended "because of me" since he wasn't allowed to be on it.

No matter what people tell me (people that know him say that's just how he is) I feel like I failed hardcore as a girlfriend. Why wasn't I good enough when I did so much for him and stayed for SO LONG? He's 28 and I'm 22 and he told me he never wants to be with me again.