BarbSue,
glad to hear you're divorcing your H- though I wouldn't go that far and say it's your T's doing- you're seeing him only for 3 months so I'd say you had to make that decision long before that.
Anyway, from what you've written it's hard to say whether or not he's abusing his power over you as a T. As far as I go, I wouldn't tolerate this kind of behaviour for my T, but everybody's different. Only you can decide that.
However, I would strongly recommend you to talk to your T about that- how should his remarks be beneficial? that he needs to rephrase that (TBH some sound really pervy) and given you have a weekly appointment what's going on, that you have to take a 3week pause- is he going on vacation?
No matter what I wouldn't end it with a Dear John letter.
Take care.