I don't have to worry at least for the age (if she dies because of that, in something like 50 years, then I will be going to die too. Not that I hope to have non stop therapy for the next 50 years, lol).
I cope with denial too. I remember being handed a test before christmas holidays that she had said she would hand me when she thought I was at a good point. I literally grieved for 3 neverending weeks (then she explained it was just to record changings).
It comforts me that it's a private practice so it is completely up to us, plus I will hopefully be ready by then and she said from the first session that I can always go back to her if I'll need therapy again or if I just want to talk to her.

But I often wonder how you really feel when you decide to have a proper termination after the work is done. If you feel actually ready, if it has to be so painful in any case...