Hi Cindy,
What a marvelous outcome for you and your brother! So glad you were a good match.
I think your endocrinologist is the person who can answer your question. If I were in your position, I would also ask if I could have my thyroid labs drawn before September, so you have this finite information.
Lots of variables contribute to fatigue, but I think it is less likely that it is related to your anesthesia this far out after your surgery, but it certainly is possible. Another question for the surgeon?
Are you sleeping well? Sleep deprivation is another consideration.
Best wishes to you, Cindy. What a wonderful life giving gift to your brother.
Shirley