I can imagine how utterly heartbreaking and confusing this is and it doesn't take away from that, but you're showing a lot of inner strength and compassion for yourself to recognise what you need from her in such a devastating situation. That really is testament to the work you've achieved with her. It's also clear that you care about your T a lot as a person and you know her really well, I mean as she normally is, which makes it harder I imagine, not understanding how she can't see what she's doing to you now and give you the chance to say goodbye. I know you know she's in a really bad place but I think understanding something logically isn't always the same as understanding it emotionally.

I just hope she listens and agrees that you deserve AT LEAST one closure session when she's able to give it. Hopefully more. But definitely that. Even if it feels impossible for her right now, and presumably it does, I'm sure she would benefit from the same. 5 years work is a long time, for both of you. I think she might well regret any decision made in the moment that doesn't offer you at least that as a chance to value your time together.

Hang in there. I know this is beyond awful.