threatened to cheat?

my husband has threatened to cheat on me many, many times. he says hes gonna cheat on me because he feels like i dont love him or care about him. he also says its because im not fun and i dont talk as much. and he says im too dumb. he says im not the kind of woman he wants. he says he feels like hes a single man living alone and im just a ghost. my husband never wants to do anything w me, he always prefer to do things himself. i told him to just leave me then but idk why he wont ever leave me at all. he claims its because of our children, but before we had children, he said the same and still wont leave me. he wont even let me leave him too at that time. now he doesnt care if i leave, but he wont let me have our kids, theyre my life and i cant leave them. what should i do? im very dependent on him...