What do I do??🥺🥺

The other day me and my fiancé got into a very heated argument I’m 6 months pregnant and it wasn’t pretty he was yelling and so was I and I repeatedly tried to tell him that I didn’t want to argue and that I was just going to cool off but he wouldn’t give me the keys which made the situation worse and he wouldn’t move out the way when I was trying to leave, after yelling some more he finally moved still not giving me the key and he then tries to close the door on me as I’m trying to keep it open he kept slamming it shut and then after just throws stuff around the room and breaks a few things, I repeat myself and tell him to stop and try to grab the keys and he screams at me again and in the heat of the moment I slap him across the face…. I didn’t mean too and it wasn’t my intention to try and hurt him but I feel terrible I got defensive as he was trying to close the door on me and when he started throwing stuff and breaking stuff and I slapped him.. After that happened he stopped yelling and slowly went outside, I apologized to him and he accepted but I still feel like crap.. I get it that I should feel like this because of what I did but it wasn’t my intention I just don’t know what to do, I’ve never been one to get physical🥺🥺