When you say the blood test is positive, do you mean that there is no obvious problem? If so, that is quite common. Could you post the details of the blood test?
As for your joint pain, you can recover. I have had some joint pain (mainly my hips) but happily it has cleared now. Insomnia is a regular problem here but also most seem to improve.
It is a depressing position to be in, I know but you have to pick yourself up and focus on the improvements or the potential for them. You say that your joint pain is better and with time it could continue to get better.
Are you avoiding 5ar inhibiting foods? I would suggest that if you feel you may have crashed a second time that you should be careful with your diet.