First, I would like to say that you are not being a wuss. This is a hard condition and treatment to go through. Also, our bodies are different and respond differently to the medications so some people have few or no side effects and others have intolerable ones. You will find a lot of different experiences and helpful suggestions searching through this site. I know that I certainly have. It sounds like both times you attempted the medications you started them at the same time. Is that the case? It can be helpful to go on them one at a time, separated by 1-2 weeks. I started them all at once initially, and I had to stop them all when I had an intolerable side effect. Going back on them one at a time (azithromycin, then ethambutol, then rifampin) allowed us to identify that it was a specific one that was causing the problem. I could then replace that one.
Do you have a pulmonologist and/or ID doctor with experience treating MAC? That can be very helpful in working through different options and deciding what treatment plan works the best for you.

Have always heard about digestive issues on the antibiotics. This was the first I heard of leg & back pain. My leg pain has gotten worse since on the antibiotics. Quests I need to ask about that. Thanks for sharing