It's like a nightmare

I asked my SO yesterday why, when we were in the midst of an argument about a month ago, he told me he "gave me this baby" and then last week he asked me whether or not the baby will have his last name. It never came as a thought for me, for the the baby to not have his last name unless he didn't want the baby to have it. He replied by saying that he didn't think I wanted the baby to have his last name, but he never asked me. He just assumed, even though we have a child together already and that child has his last name...he also said not to worry about him saying he "gave me this baby" because he said it when he was mad to hurt me. What the heck?! Who says something like that to someone they claim to love😞 he knows how much having a baby meant to me, and he intentionally tried to use it against me when he was mad. Now, I kind of wonder what else he may have said when he was mad about me to someone else? I hate feeling this way. I hate that I asked. I hate that it took me a month of asking him why he said what he said during that argument before he answered me. Not really sure where to go from here, honestly. Just venting, I guess