You are right – your journey sounds like what a lot of us have been through. My daughter is even younger than you – 39 – and has bronch, a diagnosis that took years. Her docs are looking for a genetic component, because she is the 3rd known generation in my family.
Susceptibility tests for your MAC are a must, else you are putting yourself through this medication torture with a chance it might not do any good. But the doc may just have started the typical regimen while waiting for the susceptibility results, which take at least 2 months. Definitely revisit the vision and hearing with the eye & ear docs. These should also be scheduled regularly throughout your treatment. As for the GI issues, I recommend a good probiotic supplement to help – not perfect, but better than nothing.
As for the future:
First and foremost, as the infection is brought under control by the meds, you should get energy back. In my view, the trick is to be as active as you can, even if you have to push through the fog/sluggishness.
Yes, bronch & MAC are lifelong conditions, but so is diabetes, rheumatoid arthritis, kidney disease… Every one of us will have health concerns as we age, the key is to manage them in such a way as to live your life to the fullest. That means saving your energy for the things most important to you, and letting other things go. It sounds like your two main concerns are needing to continue to work, and being able to do things with your grandchildren. To focus on those, you may need to let other things go – maybe gardening, cleaning, church or other volunteer activities, … need to be pared back or turned over to someone else. Shopping is an area that is easier then you might think to save energy – take advantage of the numerous on-line ways to shop, even including ordering groceries for delivery or curbside pickup (maybe on the way home from work.) Ask your kids for help – maybe play with your grandkids (even a board game or read to them) while their parents clean your house, do laundry, yardwork or chores for you – like you would help them if they needed it. If your home is too much to care for, consider downsizing to something more manageable.
Above all, if fear and anxiety are crippling you, get a little counseling – dealing with a long-term chronic condition is stressful, and gaining some insight and tools to help yourself can be a lifesaver.
Good luck to you as you undertake this journey. Keep living your life to the best of your ability and bring your concerns back to the group.