Your boyfriend was looking for a way out of the relationship, and unfortunately, by hitting him (however lightly you think the slap was), you gave him a way out.
I understand that you are exhausted from having a baby and a toddler to care for, and your boyfriend antagonized you. But…there is no reason to hit anyone, and you should have walked out of the room or tried to get away from him when he was taunting you, rather than striking him.
Signing up for anger management class is a good idea. I think that the best you can do right now is to just focus on taking care of yourself and your children. I’m guessing you’re not sleeping much with a 2 month old baby at home and a toddler. See if you can get some family help so you can make sure to get enough sleep.
If your babies’ daddy sees that you’re living well and taking care of the children, he should want to come back and work things out. However….if, as I suspect, he’s been looking for a way out of the relationship, and taunting you helped him accomplish that, then he’s probably not coming back to be with you. Time will tell, however, and while I know that this is going to be heart wrenching for you to wait and see if your boyfriend will come back for good, you have no choice.
If he hasn’t come back after a month or so, file with your court for child support and visitation, so you can at least get some help that way, and take your anger management seriously. You don’t want to make this mistake again. 😥