OP, I haven't read the full thread, only a few of your replies, and you obviously feel terrible.
I think you said you apologised which is good. kids need to know adults make mistakes aswell. Is you're son at the stage of understanding actions and words etc? My son is four and without making you feel worse, he wouldn't hurt me and if he thought he did, he'd be upset without me saying anything.
My ten year old is ND, as I said I haven't read the full thread but I'm sure it's been mentioned. He would fly off the handle and hurt me or himself when he was this age.A wooden train to the nose was one incident, and a bloody Thomas trackmaster knitted into my scalp while I was carrying him before. Now he's older he he still might hurt himself.but not anyone else.
you're in the thick of it right now. I think you should get On the phone to your health visitor, I know they have a bad rep, but mine helped me so much.
I'm sure it's been mentioned aswell, but is your son jealous of your daughter? Could you get him a doll so he can mimic you? We're going to bath your doll and baby sister now, baby needs some milk now, does dolly?shall we play together? Etc.
sending you best wishes x