What can I do to handle my dog?

It could be that your dog thinks that your baby is his baby. My friends dog was given a small toy for its birthday by my friend, and it thought it was its own baby. I can’t actually remember what the sort of condition is called where the dog thinks it is its baby though. But his dog wouldn’t let anyone touch the cuddly toy, or go near it, or have anything to do with it. It would bark, scratch or even try and bite you if you went near it. Which is why I think it is similar to your dog! What my friend did, was when their dog wasn’t looking, they would take the toy from the dog. I know it sounds mean, but it helped. After about a month, the dog started to not be fond of the toy, she still played with it, but not as if it is her baby. So maybe, you could try not letting your dog see your baby as much, not be in as much contact as it usually is and hopefully after a while but not too long, your dog will be how it used to be :-) I hope this helps and that picture of your baby is soo cute :3!