You feel like you've been through the mill and this relationship has completely exhausted you, but you're finally starting to feel free again! This kind of destructive relationship with an unattainable man (married, immature, tormented, self-destructive, etc) was never going places and you've done the right thing by getting out of it. Breaking up was the only thing to do.
Questions you need to ask yourself
Why did I stay with him for so long?
Why did I carry on the relationship when I knew it was never going to go anywhere? How did I put up with a relationship when it became more and more humiliating, fatiguing and destructive?
What to learn from it
You gave all you could and more without thinking what it was doing to you, because you don't think highly enough of yourself. You can't force someone to change, and you need to accept that. But you're free, you're relieved it's over and things can only get better. You have a right to be happy, and you've just reclaimed that right by breaking up with him.