The prognosis is that you need to learn to live with it, live as comfortably as possible, and take care of yourself. Since our disease is not recognized as it really is, we spend most of our money on doctors, clinics, medicines and supplements on top of often not being able to make a living. Much of the money is wasted on things that don't work. Then we find something that works for us. The best way to live is to have a support system, even if it's small. If not human then animal. Beauty of some sort, things that make us happy should be in our home space.
I was 24 when I contracted it. That was over 30 years ago. Now facing my elder years I expect it to remain the same with some variations such as in the last 5 years I was diagnosed with cervical arthritis. Unless a cure is found it is not likely to get better. However I have begun taking new medications for head pain and for myalgia and nerves that have made a real difference.