Remember: you can't change HIM, only YOU. And right now, HIM isn't in a place to notice much about YOU.
Think of it this way:
Random stranger walks up and beats the holy stuffing out of you while wearing street clothes. He then fixes his hair, puts on a suit, and comes to the hospital to show you (while you're incapable of getting away) that he's a changed man because ... well, he LITERALLY changed while you were getting operated on, thus "changed."
That's all he can see at this point. YOU feel different because you're starting to take responsibility and acknowledge these things you did to ruin the marriage, but he just still sees the person who kicked the crap out of him.
I know you don't want to hear it, but it takes time. With enough perseverance and continued good behavior on your part, he WILL notice, and he will be much less snarky about it. It just takes time and dedication. Are you up for it?