I can relate. I experienced some of the very same emotions you describe after ending with my previous therapist. It is grief. It is like a death. I'm sorry for your loss. Very sorry.

My ending was good, I can only imagine how traumatic it would have been to have a bad ending.

I spent a lot of time with my current therapist talking about my old therapist.

As far as moving this along, well, I so wish I had a magic forgetting elixir to give you, but I don't. I think you will likely continue to think about her, but the pain will lessen. I promise. It will get better.

Grief and trauma just have to run their course. I think you are doing a really good thing for yourself by talking about it with your current therapist. It's been my experience that they "get it". At least in terms of how deep the relationship between a therapist and a client can go.

Try to be very kind to yourself. Each day make an effort to find/do/see something that gives you joy.

This is not a life sentence, just a thing you have to go through. It'll get better.