I think it's a perfectly understandable fear when you're attached, especially to an older T.

A sudden health crisis caused my T to retire. Although we were winding down our therapy, we had not officially acknowledged it as a termination phase. When he returned after his hospitalization, he made the decision to retire, and we met a few more times and talked about all of these things thoroughly. I was very reluctant to "go there," but he insisted. He was right: it was his final responsibility to me, and I benefitted tremendously.

Even now, he is very straight forward with me about his health because he knows I will worry in the absence of information.