See here's the thing, a state is going to say a parent has a right to their child, no matter what, barring any provable action. Saying "he might do..." or "He could do..." isn't going to work because the position he and his attorneys could and likely would take is that the child is his child as well as yours, and he has as much right to parent as you do.
That's a very hard thing for a mother to hear because she's the one who carried the child, but that's a reality a mother has to accept. He may have said things in anger or emotion, but he hasn't DONE anything yet, and may never. If he's had a legitimate and serious change of heart and wants to be a dad, you'll have to accept that.
However, since your child is so young, you'll likely be able to have age related restrictions placed on visitation.
Additionally, please be aware that whatever you post on the internet CAN be found and used against you, particularly anything related to your character and/or your case.