I hope your ice is melting! I live in the southwest where it is usually in the 70s this time of year, but I've been whining about it being in the mid 50s and raining...guess I'll stop doing that!
To your questions, first O2 is oxygen. Some of the folks I know with NTM need O2 to breathe and are tethered to either a large or small device; I've never had to use it. I do use an oximeter at home to check my oxygen saturation. It's the same small device that is put on your finger at the doctor's office. I bought mine at a drugstore ($30-$40) and use it just to check in with myself and make sure my oxygen is good...especially if I'm feeling a little punky. Sometimes anxiety makes me feel breathless. That's a good time for me to use the oximeter and see that my oxygen is just fine and that I'm a little panicky over something else (pandemic/war/earthquakes/homeless folks, abandoned pets).

The cavity in my left lung is 7.4 mm x 6.5mm. It's relatively new and scared me a lot until I did further research. I'm praying that through exercise and good (as good as I can do it) airway clearance (along with a lot of prayer) will make it heal. I also have bronchiectasis in my right lung. It was suggested that be removed as well. I said not yet. I'm just not ready.

My colon surgery was a subtotal colectomy with the small intestines reattached to a small portion of the rectum, thus avoiding a colostomy. It has not been without a few issues, but I have a great GI doctor that I can turn to if concerns arise. I didn't have cancer. I just had a colon that stopped functioning - at all. After five years of total misery I finally consented to the surgery. I was terrified of a colostomy and remain grateful every day that that was not the outcome.

I tried the BIG 3 when first diagnosed in 2011...two years after my colon surgery. I couldn't tolerate the side effects of the drugs. My pulmonologist had me wait six weeks and re-introduce one at a time. I still couldn't tolerate the side effects. My ID doctor said that my body chemistry was not going to allow me to take the drugs. BUT, lots of folks do just fine. My dear, dear friend I roomed with at NJH took them plus had a port for another. She never missed a beat. They had no ill effects on her at all. As best you can, listen to YOUR body when/if the time comes to take them. It may take a little while to adjust to them or it may take very little time to learn that they aren't going to work for you. Either way, you will find a way to manage this disease.

I hear how important this upcoming surgery is to you and pray that it moves forward as you hope it does. I will happily answer any questions I can or just be here if you need a friendly ear. Like you, I've never known anyone that had their colon removed AND had NTM so I find this connection an unusual Godsend. My best to you, along with many prayers.