I'm afraid I couldn't get over how he's treated you.
He's misled you at the start, and several times since - including proposing and then backing out a month before the wedding?
He registered the children in his name, saying they didn't need to be double-barrelled as you would get married eventually?
He has given you various reasons, which actually means they aren't true (if he had a solid reason / convictin against marriage, he would give that reason every time. The fact he gies different reasons means he just doesn't want to get married).
He says it isn't important - he means it isn't important to him, and it's irrelevant that's it's important to you.
He's had his way for the past 29 years. And he thinks he should get his way to the end. That you should just suck it up and deal with the disappointment all your life?
He's happy for you to have your children but isn't sure enough to get married?
It's the insult, the lack of respect, the lies and leading on, the not caring about your feelings or needs... I'm afraid I couldn't respect him anymore.
He is confident he has you stuck, and you won't leave him, so he can continue having his own way. I would have to call his bluff. And mean it. If he won't make that (small) compromise for you after all this time....