Getting Past Worst Case Scenario to Beleivable Intentional Thought

My partner of 8 years left me recently, is having a relationship with another woman, and I am devastated. I see now that I wasn’t the partner I wanted to be, and have been doing a ton of work examining my thoughts, and want a renewed romantic relationship. He has said his answer is not “no” and he’s not making decisions right now, but continues to take steps to move his stuff out and separate.

My worst thought is that once he moves out, it’s over and there is no chance of a renewed relationship.

I’ve done models and can see where this thought gets me the result of “no renewed relationship.”

I’ve sat with the pain and grief, and also with worst case scenario, to feel the feelings instead of avoiding them. But I stay stuck in worst case scenario. My thoughts keep returning to “I’ve blown it and there’s no chance.” And feeling those feelings over and over is wearing me out.

I’m having trouble coming up with an intentional, believable thought that serves me and gives me a chance at the R I want – a renewed romantic relationship with him. I’ve tried “a renewed romantic relationship with him is possible,” “I am an irresistible romantic partner (to him),” and “we can be even better together a second time now that I’ve done all this work,” but they feel flimsy and the negative thought “there’s no chance” continues to rule my thoughts and keep me awake at night.