He's such an asshole but I can't be mean and I fucking forgave him I kinda hate myself for that

So for about 10 months I've been talking to a soldier. We've known each other for years though. I've told him I don't know if I'm ready for a relationship. He's been telling me he thinks I'm ready I'm just scared, we'd be too good together, he won't quit until he has won me over blah blah blah (he said a lot of this the week before he came home). So after all this time I was finally coming around to it. He couldn't wait to get home, I couldn't wait for him to come home. Then he came home. Didn't tell me about it. Didn't want to see me. So I texted him asking what the hell. He said he decided that it probably wouldn't work. That the Army would kill the relationship anyway. He didnt let me in on that earlier when he should've. We had a long talk and I told him all the ways that he fucked up. He apologized. I forgave him. Then the next day I see a post from a girl I went to college with. Turns out he had spent the whole week he was home with her. They're dating now. I know I deserve better than that. And while I'm still angry I'm not going to dwell. It was just so fucked up that he did that to me. Messed with my head. Made me come around to a relationship and then left me hanging alone. Ready, but alone.