So i dont know why my shifts seem to take so much longer then others. It could be because i never had definitive proof of anything other then that my ex left me. Dont even know for sure if he actually cheated. Although based on every other wayward he probably did. So maybe its because i just never had that knowledge of what really went down.
Yes he cheated - okay? A guy who just leaves because he's unhappy in the relationship doesn't do all that other stuff and doesn't stop being a good father.
Maybe it would help you to understand more about what's wrong with your ex if you did some reading. I know that my friend who helped me see my ex's narcissistic traits after the divorce really helped me to see my whole marriage in a different light. You might try reading The Sociopath Next Door, it's a short book and frankly, I think it oversells its premise a bit but some of the stories may seem familiar to you.
And as for moving on - the way to move on is to start doing things to move forward. I know you feel tremendous pressure, being a single mom and living with your parents and just generally not being where you'd like to be at this age. But your future starts today. I recommend you make a vision board of the life you would like to be living in ten years. Then start trying some new activities to make your life RIGHT NOW more interesting, filled with friends and energy. The more of that you have in your life the less you will think about your ex.