@sylvermoon8 Your reaction is totally normal! Especially after you read some of the issues people are having with both the illness and the treatment. That said, read what you can to educate yourself. Make sure you are seeing a pulmonologist and/or infectious disease (ID) doctor who specialize in treating MAI and bronchiectasis. If yours is not, ask for a referral to someone else - this is not an easy thing to treat. My pulmonologist just "handed me off" to an ID doc because he had used all his usual protocols and they weren't enough.
As to the source of your infection, it COULD have come from gardening, OR your mulch, OR your soil, OR your tap water, OR a hot tub or swimming pool, OR from any of the above encountered as you travel. NTM (non-tubercular mycobacteria) are EVERYWHERE. You cannot completely avoid NTM without living in a bubble. The key is to take sensible precautions about exposure, eat a healthy diet, get proper rest, practice good lung hygiene as recommended by your docs based on the extent of your disease and symptoms, take prescribed antibiotics...and continue to live your life.
For example, I am and always have been an avid gardener. I am pretty sure the origin of my infection is exposure to soil contaminated by feral chickens scratching, nesting & pooping under my fruit trees in South Texas (winter home.) Therefore I no longer garden there, and have only a few potted plants. In addition, I close up my house & stay way while yard work is done, and the gardener washes down the patio afterward. At my summer residence, I continue to garden, wearing gloves always and an N-95 mask when it is dry, dusty or windy. I pay a young man to do the Spring cleanup and mulching and stay away while it is underway. I shower and launder garden clothes and gloves at the end of each workday, and replace the mask after 6-8 hours of use or if it gets wet (OSHA recommendation.)
In addition, I continue to volunteer, travel, hang out with my kids, grandkids and friends, and generally enjoy life - stopping to rest when my body demands. I try to eat well (a struggle on the Big 3 antibiotics taken daily), avoid being out on dusty, windy days (no more desert hikes) or wear a mask, stay out of hot tubs, take quick, non-steamy showers, neb and use my meds as prescribed.
One key I really believe helps me stay well - I, and everyone around me, practice excellent hand-washing & food/living space hygiene. This is easy at home, both my daughters are practicing nurses in high-risk environments, so they are relentless. Away from home, I try to be cautious, and if I'm going to be around new people, I try to do a little low-key, gentle education. I couch it in these terms "I have a compromised immune system. Getting a cold or the flu is devastating - it turns into bronchitis and then pneumonia and it puts me in the hospital. There are others in our little community with the same problem due to other illnesses. Please help us by thoroughly washing your hands, and by making sure all surfaces are thoroughly sanitized before every event. And please don't bring or handle food here if you are ill. Even better, stay home if you are ill, to avoid spreading germs..." Last year, after our first full season of this approach, we saw a noticeable decline in the number of illnesses that "went around" the community.