Great post. You have a great plan. Don't waver. You'll be much happier in the long run if you don't. You've got over half your life still ahead of you. That's awesome. Live for you and for the kids now. She's definitely living for herself and not your family. Keep getting in better shape, that's really good for you. Exercise releases endorphins and is the absolute best way to fight depression/sadness. Far better than medication.
It really is going to get better for you. Open your eyes to new opportunities to grow, learn, love. Become a new you. The you that you used to dream of being when you were a kid.
Stay the course, your plan is solid, and you're doing well. No anger. No crying. No begging. Stay the course.