My baby having my last name not dads..?

So me and my babies father are not together anymore and haven’t been for a while now.. this is because of his actions and the way he has treated me whilst being pregnant.. first of all he knew I wasn’t on contraceptive so he knew this was bound to be the outcome! When he found out I was pregnant he changed a lot and treated me a lot differently.. never messaging me and being really off.. I already have two children from a previous marriage so was really worried about having a third baby with a man that won’t want anything to do with it so I panicked and didn’t know what to do.. when I spoke with him he said if I couldn’t get an abortion on the NHS then he would pay it.. this upset me like you wouldn’t believe so I distanced myself from him for a while.. eventually I got in contact with him and said he could come to the scan.. he did and all was fine but he then started acting like a child and doing things to annoy me so I snapped and told him that his actions are not normal for a man his age so he walked out on me AGAIN and didn’t get in contact for weeks!! In those weeks I found out I was having a beautiful little boy and wanted to name him so I did, that name has stuck now and everyone calls him it so I’m not willing to change it! My two children I have now have my last name so I want this little boy to have the same last name as me and my children which I think is fair! He now after weeks of having my babies name set in stone wants me to change the middle name to his surname which just sounds Chavy and horrendous so I’ve said no to which he has thrown his toys out the pram once again! Basically what I want to find out is am I being unfair after all he has put me through and the stress he has caused! I feel like he doesn’t have a rite to even have an input after him saying he doesn’t want my son and to abort!!!!!!! He can have as much input when the baby is here and spend time with him but I’ll be damned if I’m changing his name I’ve chosen for him!