I could really use some input

[ElaineM]

I can't tell you what to do, but I also like how you are considering all options and possibilities. One way to find out if the nodule in the lung is cancer is to try to get a PET/CT scan. Sometimes CT scans can't definitely tell what something is, but the PET will probably be able to determine whether or not the nodule is cancer or if there are any other areas of cancer that have not been identified.
I like Dr. Salmon's idea even if he hasn't seen all your reports. He is one of the world experts on her2 positive breast cancer and he is still doing research. If Dr. Salmon thinks T DM1 will help that means alot. Perhaps you can find a way to get your reports to him and if he can't talk to you in person maybe he would be willing to discuss your situation with your doctors or talk to you on the phone for a few minutes.
It does sound like this is going to be quite an experience for you. The integrative medicine is going to help you get through it too.
You make the final decisions no matter what the doctors think. Do what your intuition tells you that you need after you talk to all the doctors and get all the opinions you need.
Take good care of yourself. We are cheering for you !!