I have been having almost the same exact issues, I have days where I hobble around at work and then a few days later I'm fast walking everywhere without any pain. I described it to my doctor as being like waves, sometimes it recedes but it can come back hours or days later and this rash near my eyes isn't going away but at least it hasn't flared up as bad.

After getting minor improvements with the rash and no change to the pain when it shows up I'm finally convinced to tell my rheumatologist since he already treats my fibromyalgia.