Sounds like you also have an implicit project to improve your health and vitality.
I don't wish to pry into personal health matters but though you feel you may have tried everything, it's likely that there is a solution or at least ways to improve your situation that you've not yet discovered. It's just a gut feeling on my part but I don't believe that you have to just accept your current condition as a permanent fate.
Perhaps you might consider exploring alternative forms of medicine like acupuncture, healing touch or reiki therapy. I went through an allergy elimination therapy called NAET a number of years ago and no longer suffer from seasonal allergies or have allergic reactions to penicillin (which I developed in my early 20s). These therapies have a common goal: to remove or correct blockages in the body's energy pathways. Eastern medicine blames these blockages for a wide variety of ailments that western medicine calls "diseases of unknown origins". I also undergo regular chiropractic care; it does wonders for pain relief and keeping the sinuses open and flowing (helps to prevent sinus infection or chronic congestion).
As for GTD advice in the interim, I second what Katherine says. Make the best use of your time given the energy you have in the moment.
Best of luck,