He says he will do anything to work on the relationship? Great. Now is your time to take control.
Ask him to move out for a few days to give you some time to think. You cannot really listen to your gut instinct when he is there, hanging around, looking sorry for himself, using emotional blackmail.
You need to get your thoughts straight, separate what you want from want you think you will be able to live with.
For example, you might want, with all your heart and soul, to work on staying together and rebuilding the relationship. But, in reality, you might not be able to do that. It might just be impossible to live with.
You deserve some time to yourself. He should respect you enough to give you some space. Ask him to move out and make arrangements for him to still see your dd.
It will give you a taste of life on your own for one thing, it will give you breathing space and time to adjust to all this new information and it does not have to be permanent. You can have him back whenever you want.
He says he will do anything. Ask him to do this one thing for you.