It's such a deep kind of grief, and made so much worse (in my opinion) by how disenfranchised it is. She's not dead, she's not an ex romantic partner or long time close friend. Which many people see as a more "legitimate" grief. Heck, even therapy-goers (who are unfamiliar with attachment wounds and depth therapy) might not understand...

I'm so sorry you're hurting. I don't know much about your work with her but I know it was deep. She left you mid "open heart surgery" in such a callous way.

I know I'd be devastated if I was in a similar situation. I'm reminded of "@here today" who used to post here about their T had basically ended therapy very abruptly too.