This is such a hard situation and I'm sorry you're going through It.

Thank you again for your immense support

How do you feel you're coping generally with your life at the moment? Could that be a deciding factor whether you see another T in the meantime or wait it out? If you feel you're managing ok maybe see how you go with your pdoc's support as that could give you some insight into how you might cope long term when your T retires.

Actually, the only part of my life that I'm super stressed over right now is M. being away, and the insecurity I feel about her absence and her lack of reality acceptance. By that, I mean that she doesn't accept that she will be out for a certain amount time and stick with that, rather than the "I'll be back in a few days" repeatedly.

There are definitely deeper issues I want to work on, but everything is on hold.

If you're not coping that well, maybe the offer to see another T at the clinic might be good to accept for now. You might take to the new T better than you think and s/he could be a valuable source of support while your T is off and perhaps longer term.

At least I know the option is available.

Whatever you decide, it does seem that unfortunately your T's health is very unstable at the moment and you may need to make a decision based on not knowing how long term the work with her will be. Or at least that would be my concern in your situation.

Exactly. That's my concern, too. Very much so. I can't relax, knowing that at any moment she'll be gone for weeks - or months.