OP here. I've really turned a corner. I was feeling like a loser, thinking "why would anyone want me"? His comment about not wanting to date me because he deserves more for his life, in hindsight, is a really, really f***ed up thing to say. Making me feel less then, or like a liability, because I have children? Please.
I've started embracing my role as single mom and valuing myself. Working out more. Reading new books. Enjoying my kids more. Branching out.
I've also started reflecting more on his sh**ty qualities and behaviors, rather than keeping him on a pedestal. It helps put everything in perspective.
Thanks for the support all.