They are your kids, don't let anyone tell you different.
She made her choices. They were painful choices, but she made them.
I know you feel hurt. But you need to fight for these kids. They need you in their life. No one is perfect. Everyone makes mistakes. And we each have to account for those mistakes and what damaged we may have unthinkingly caused to our community. But your children are innocent, and they do deserve the best life possible.
Don't blame them for your guilt. Don't punish them for your feelings. Release them from the generational pain that has been thrusted upon you to resolve. Give them a better life.
I know you feel dependent on her. I know how you have trouble envisioning a life without her. But this is no longer about you and her. This is about providing for your children. She doesn't have the same opportunities you do. She has made different choices.
You have the opportunity to secure a form of stability on behalf of your children. And no matter what anyone says they are your children. You are going to feel pain. You are going to feel angry. You will be repeatedly tempted to lash out and punish others for the pain you've experienced. You need to remember this is no longer about you. This is no longer about you and her. This is about the life and opportunities you can provide your children.
No one envies your position. But you are smart. You are kind. You are thoughtful. Try to slow down and give yourself an opportunity to process things. Long walks alone in the park without headphones always helps.
This is about your children and the world you can shape on their behalf. Fight for them. We have your back.