A few months ago my knee started hurting terribly, I couldn't walk without limping. It was so out of nowhere that a specialist diagnosed it to be psychosomatic.
He first told me to quit my job, because that was causing too much stress, and look for a new one.
So I did. And that actually helped at first.
But then the pain came back even stronger. That was very frustrating since I already had quit the job and, apart from my mental illnesses, there was not much going on that was causing me stress.
So I decided to just ignore the pain, and even continued working out (best to my ability + taking lots of ibuprofen beforehand). It still hurt for a week or so, but nowadays the pain rarely comes back.
I guess what I'm trying to say is that what helped me was focusing on the fact that the pain is psychosomatic and choosing to ignore it.
Not sure if that's a recommendable way to deal with it, but still wanted to share. : )