My abusive ex moved on

It’s been about three weeks since my ex and I broke up, and he’s already dating someone new. It hurt me when I found out. They look really happy in pictures, and I’m just thinking. He’s going to treat her the way I wanted to be treated, he’s going to love her more than he loved me. I remember back in high school when everybody said she looked like me at a quick glance. I’m so confused on why he’d choose someone who looks similar to me. And I’m also curious about how he could move on so fast. I know I shouldn’t be sad because he was controlling and abusive and etc. but why wasn’t I good enough for him to make me happy the way it looks like it makes her? I tried my best not to make him mad, and he said it was always my fault that lead him to being the way he would be. He said I brought out the bad in him and I feel so horrible.

How could he talk to me this way and treat me like shit and be happy with someone else and act like we never happened? He doesn’t deserve to be happy (I know this is mean to say).