Block him. Keep yourself busy with other things, stay occupied with other stuff for the first few weeks so you don’t go back to him out of anxiety. He sounds like a disaster.

As about attracting such people it could be influenced by how you were brought up etc but I am not about to analyze your childhood to death.

The way I look at it we can’t help who we attracted, but we can help who we enter a relationship with. People reveal themselves pretty quickly. Within first few months of dating. You just have to pay attention. Not rationalize and not look for excuses. Have a list of deal breakers, get out as soon as you see something is off. It’s important not to become intimate right away, don’t move in and certainly don’t marry. Good therapy can help to address the roots of it and your response to things

Good job leaving him, now stay away. Hugs