I'm so sorry for what you are going through, divorce sucks . That being said she relinquished custody of her own children, to me this speaks volumes.

Should I start valuing myself more >>>> YES 100% and realize that I don’t want this person back after all she has done to hurt me and the kids? >>> That sounds like a great choice, she may have psychological issues but IMO You need to take care of your family first and do what is best for them. You didn't abandon them she did.

Be strong you've got this. At least you have a great job in Colorado which would give you all a nice fresh start. I hope you are still taking it, would be the best thing for you all. If she were to try and come back she would have a lot of work to prove herself at this point and would you really want that anyways?