Guys say the same shit

So I was in an emotionally and mentally abusive relationship for over a year. I finally got out of it. He'd always beg me to take him back but I finally left him at the beginning of this month. What I don't understand is..
​1. Why does he tell people he left me when I'm the one that broke up with him.
​2. Why does he call me names and say hurtful things to me?  "Like slut, whore, you're looser than blah blah, I'm glad I left your slutty ass, you're ugly, etc"
​3. Why did he move on so fast? We just broke up like 2 weeks ago.. Not even and he's already dating another girl. I try not to look at his social media but today I just had the feeling there was posts since he got mad at me for a post with a guy I had a thing with. And I saw that he posted 2 wcw of a girl that he calls his gf and she comments and stuff
​4. Why does he tell her the same stuff he told me? Ex) you're he best gf ever, your kisses are the best, etc