Being positive about pain

Having climbed out of the depression pit, I am now struggling to be positive about pain. It is constant pain to varying levels, getting worse at night.

It is hard to describe neuropathic pain, but it is like pins and needles (and stiffness) in my hands, feet, legs and even mouth. Most painkillers have horrible side effects, and if I take them in the day I am sleepy or I can't even feel my legs.

I keep hearing about these wonderful Tsaddikim that remained positive and upbeat when suffering tremendous pain or terminal illnesses. One always wonders how you would react under those circumstances. Well for sure I am not on such a high Madrega. I complain a lot and can't accept my situation with joy. Give me an answer, what am I doing wrong?