Hi! I hear you! I am at the very severe stage, and have been doing 6 minute walk tests usually every six months for several years. My pulmonologist's staff sets out cones down a long hallway, and you just walk, holding a pulse oximeter with a large readout, end to end, as long as you can, or until six minutes are up. You walk at your own pace. Since I use oxygen to sleep, I use it for the test. It lets me go farther than I would be able to without it.
The last several I have not been able to complete. I have dreaded going because of it, even though it's not for punishment, and there is no failure. The test is strictly to measure how far you can get before you are out of breath.
The nurse jots it down, and the doctor compares it to the last time, or uses it as a baseline. The last time, the doc said I went farther in less time. Have no idea what that means in medical terms, but it sounds good.
However, I have been walking on a treadmill for a couple months, and I am now able to walk for 8 minutes. I have my next appointment the end of July, and I don't dread it.
By the way, welcome to the group. You will find lots of important info, friendly voices, and interesting stories. It is addictive. Please let me know how it goes.