Broke up with fiance over Baby's last name

For context, my ex and I got engaged, then found out I was pregnant a month later. Together for 4 years. Wonderful relationship until we started facing the more serious aspects of merging our lives in a committed way. We planned on a quick wedding so that I could still fit in my dress. I ended up having to cancel the wedding due to questions of his maturity in handling his mother overstepping, and a number of other issues. He only wanted to postpone, but with days left until the ceremony, I had no choice but to call the vendors to cancel. I paid for everything. Can't afford a second wedding. So.

We've been on the rocks. Steadily coming back together to talk and entertain the idea of future marriage. I wanted to see signs of maturity before that happens, i.e. him getting his own place and paying rent for the first time, managing and cleaning his own space, etc. I've let him live with me for almost all of our relationship. Asked him to help with the power bill. Just half of the power bill. He paid it once and that was the end of it. There are other issues I'm concerned with, but in the interest of time, I'll keep it brief.

We had my 17 week appointment a few days ago and found out we're having a baby girl ❤️ He was very supportive during his visit, and it gave me a glimpse of hope. While we were waiting for the doctor to come in, we started talking names, and eventually he brought up her last name. I'd mentioned when we were first reconciling that I want to share a last name with the child I will be birthing and taking to doctors appointments. He seemed to let that go at the time, but then when I doubled down and said if we aren't married, I'm giving baby girl my maiden name, he shut down and turned icy. That's how he usually is over anything that doesn't go his way.

Where I might be in the wrong is that I shrugged. It's always been an uncomfortable/unsure gesture from me, especially since I didn't think it was the time or place for that talk. He saw it as disrespectful, and like I didn't give a rip what he thinks. I didn't think this was going to be such a huge fight because I was still wearing his ring that I waited years longer for than I should have, and still had marriage on the table with him. Why worry about a hypothetical if marriage is where we both say we want this to go? The doctor came, then I was about to get a blood test. The plan was that we would go to Costco right afterwards. That was always the plan. He wanted to go straight home after, and asked very coldly if I needed him there for anything. I simply said "no", because technically, him being there at all is unnecessary if he wants to leave so badly. He snatched his waterbottle out of my hands and left.

I'd never felt so stupid for still dealing with this. I went to Costco alone, brought the Costco crap in alone, let the dog out, even though he was already home, and walked the dog alone. He did ask if I wanted any help with the Costco stuff. I said no, but I was still upset. He'd said days ago that I wouldn't lift heavy things while pregnant when he's around, but here I am doing it already anyway. I needed time to cool off, both physically and emotionally, so went to my room to eat my pizza under the fan. Took some peaceful time alone, but he was shocked that I was upset with him.

When I came back to talk, I explained again, I don't want to have a different name than my own baby, as her mother. I understand that he feels the same way as her father, but this is where we're at. I'm at this point an unwed mother, and I thought he would be at least a little accommodating of me being in this situation. He said I see myself as the only important parent, and everything is my way or the highway, then gave a long speech about how I'm going to be alone because no man wants to be with someone who only ever has their way, etc. I asked, "do you really think that scares me?"

The kicker in all this is that in the handful of times we've broken up, he's initiated the actual breakup whenever I put up a hard boundary. Like he wants to beat me to the punch. He started hinting at it again this time, and I just didn't feel like negotiating anymore. I handed the ring back to him and said I'm not dealing with this anymore. It was a relief honestly. The whole pregnancy has been nonstop intense arguments between us, and I've worried so much about how the stress might be affecting baby. He hasn't seemed the least bit concerned about that, but I'm finally done with it. He has always come back with apologies and goading me into apologizing for "my part" which is whatever scrap of gaslighting he can come up with. His favorite lately is that I don't trust him.

This time is different. He left saying that he's still young (he's 27 and I'm 32) and he can start over easily. I told him go right ahead. I went to get my key back and he flicked it into the air so I had to pick it up off the ground. He hasn't messaged with any apologies or excuses thankfully, and it's been a few days. I'm heartbroken that baby girl's family is done before she even gets here, but probably better now than later. Oh and he's apparently goimg to take me to court over her last name. With what money, I don't know. He's currently unemployed, and is about to learn what bills are is since his family isn't housing him long term. Anyway, I don't know if this is just a rant or looking for advice, but I can say that I have an incredibly supportive family who I am so grateful for. They've been warning me for years. My dad was so relieved when I canceled the wedding. Everyone was.

All this to say that everyone's situation is different, but I'm going into mine single. And I'm ok with that. Pregnant or not, alone is ALWAYS better than with the wrong person.