I'm sorry t's leaving is coming up... it always sucks if you've worked well together, but it hurts a lot more when it comes in the middle of struggles.
I'm glad t is being helpful with the transition. I hope it works out for you. I've never had a t be so involved in the transition (it's always been because of ending internships or me having to find another t at another agency, or a cross-country move...).
Is there anything you think might help you more? Would you feel more comfortable telling new t how to read you and what is generally helpful? I've gone in to seeing a new t with a list of things I definitely wanted them to know about me, especially if I was in a vulnerable place when starting with them. The t's I've done that with seemed ok with it, and it seemed to help.
Hope this transition goes ok