Did he tell you why he thinks you should be the one to leave?
Anyway, if he thinks you should seperate, but he won't leave, you can almost bet that he will continue to throw down barbs. the'll probably get worse, and more frequent. I would guess that he is going to do his best to make you be the "bad guy". (Which is probably why he won't leave.) Be ready for it, because it won't be pleasant.
I don't think you want to aim for less confident, just more understanding. Admitting that you have fault is ok, but don't let him give you all the blame.
