Now you're just having a pity party. You are not wrong for feeling that way and you know it. You are wrong to try to make your ex responsible for those feelings. Feel any way you want but know that it is you feeling it and no one else's responsibility.
We have all gone through this and I still every now and then indulge in the "what if" game. But that's it, I indulge in it and I know the outcome can only be frustration and sadness.
You can't change the past and you can't force someone to see changes in you. If you have changed then it is for you and your children and future people you will meet. That has to be enough.
Maybe when your kids are grown and gone and your ex has time to think, she may realize you weren't all bad but that could be a long time in coming, if ever.
Never expect anything from your ex. You don't get to. She certainly doesn't expect anything from you. Treat her as you would an acquaintance. Be polite, kind, and considerate. Do not be too familiar or needy. Who know, in time she could come around. But never plan on it.
Another suggestion. Schedule your "mourning" time. Do not let yourself dwell on the situation but instead plan 1 hour a day to think about it. At first, it takes all your self control to tell yourself "Not now, I can think about this a 6:30" ( or whatever time). Then when that time comes, sit down and go over your thoughts, cry, scream, whatever you need to do. You will find that the more you do this, the less you dwell on it during the day and eventually you have to really work hard to get yourself to sit and mourn. The need fades. This really does work if you give it a chance. It also frees you up to be the person people remember you as and not the forlorn guy who got divorced. It makes a difference.
