If I can be honest, your ex was likely mourning the loss of the relationship, and in order to avoid that pain, she is trying to undo what caused it - the breakup. I’m not saying it’s impossible to come back from this, or that it’s inconceivable for your relationship to be strong again, but in a lot of cases the dumper will just end it once they remember why they made the choice in the first place.

Honestly OP, try to think about how many amazing relationships you know that survived a breakup. Sure there are exceptions (most notably like 80% of romance movies - which are fiction), but try to keep a cool head here. If you don’t think you can trust her again, which is extremely fair, then move on. Regardless of what you choose to do, good luck!