What I see here is how people living with disabling chronic illness have learned to cope by changing their perceptions, their health regimen. @ariza9110 I would like to share that I became ill when I was 31 and now I'm 67. I can tell you that I had extreme chemical sensitivities when I was in my 30's. In addition to 4 autoimmune illnesses, I had cancer. I lived in an old apartment with terrible black mold while going through radiation treatments.
Here's what I've experienced; brain fog was initially very difficult, but it didn't last. I had gluten sensitivities and was gluten free for 10 years, then that cleared up also. I have 3 decades of dealing with chronic problems that I learned (somehow!) to cope with, then things change.

I understand feeling hopeless. But following suggestions by folks here sounds like a good place to start. My feeling is there have been symptoms coming and going , the most important thing for me has been creativity. People are creative with their approach to their illness, they are learning natural medicine to help others (@rainerhans). I became a certified chair yoga therapist because I couldn't find a good yoga therapist when I moved here. Now I offer free classes for seniors and the disabled.

When I turned 60 and realized half my life I've been disabled, I was very surprised to learn that if I had to do it all over again, I wouldn't change a thing. I've become a published poet in this time. I love the natural world. I love baseball...

Find even one thing a day that brings you joy. That's how I got through my depression in those first 10 years. Gradually, I looked forward to that one thing and built on it. Even with illness we can have passions for love, joy and creativity.

This is hard won advice.