You seem to have a pretty good understanding of the future pitfalls. I would agree there is a risk there. And it feels pretty awful to be used emotionally.
You are right contact with her is unavoidable. You have children and logistics. No contact to protect yourself while you are vulnerable isn't an option. There are other ways to help you with these vulnerabilities - they aren't as quick and easy but long term will give you a better foundation. During all this you are going to have to grieve too. That's probably the hardest. Be real kind to yourself on that front.
You need a plan LS and a support system. How's your support system - this is the most important?
A plan for yourself and your future: Legal, reviewing boundaries and the detachment lessons (right hand margin---->
A plan for communication: SET, DEARMAN, validation
A plan for the kids: communication, parenting
A plan for how you approach her: Karpmen triangle, boundaries, validation
Which ones of these workshops have you read?
https://bpdfamily.com/message_board/index.php?board=36.0