I slept maybe 3-4 hours per night for ~7 years.
Then one day I saw someone on Hacker News mention Dr. Sarno's book, and it changed my life.
I convinced myself that the pain was all in my mind. I'm still not 100% symptom free, but I now have far more good days than I do bad days.
I read all of his books and I try to re-read the first one at least once per year.
It become convenient for me to blame my problems on my chronic pain. I fixed all of that by simply changing the way I thought about the pain.
Now, whenever I feel the pain flaring up, I just make myself focus on my breathing rather than focusing on the pain. And then I simply forget about the pain.