He divorced about 9 months ago. For the next months, he did a lot of crazy shit—like lying about having a restraining order and blaming me for the divorce.
Then, when it was time to meet his ex-wife for the divorce, I don’t know what happened to him, but something clicked in his brain. He decided to take her back and tried to convince me to help him because he claimed he was a changed man.
All that was bullshit, and now he keeps blaming me for it.
During these months, he went to Cuba and proposed to a chick with two kids that he’d met less than a month before. After that, he kept crying because his ex-wife left him.
Note: I know divorce can change people, but he was a horrible person even before that.

What can I do about him?