HI Tumbleeed,
Well, ok, maybe mountain climbing might be a tad ambitious alright, but going to the base of the mountain and enjoying the view and fresh air might be nice, or as far up as you can manage.
I'm not saying that it might be years for you, months maybe, but just how long, who knows! You seem to be a fit person if you do mountain climbing, so I can imagine this sort of level of fatigue must be very frustrating for you. At the same time, just because you are fit, it might mean that you'll get over it faster and recover at a faster rate. Basically, nobody can predict it, and one should mind one's body and take the time to heal. However, a bit of pushing and challenging does no harm at all. In fact I think it might be a good thing to push a little form time to time. But maybe not just right now.
The fatigue that I experienced did not remain at the same level for the entire 'fatigue period'. As the months went by I was able to do more and more, but always minding that I would not step over the fatigue threshold. Doing so would have meant a few days of little energy. It really was a time of thinking what I could do and prepare. Going out socialising or for meetings meant a nap before, and a quiet morning the next day. It's all about stepping back and see what you can do. Takes some adjusting, both in terms of scope and ways of doing things. But you'll get used to it, and soon you'll find yourself back to a level of energy that might even surpass what you had before treatment. Be patient. You'll get there. Remember, this is the start of a new life, and you need to see how you can return to as close as before as possible. Might be hard to say, but it may well be the case that it will never be quite the same. Close, but not the same. For me, I feel better now within myself than I have for years and years. Treatment is just a step in the process, now you're in the next stage.
Ciao, Lorenzo