What Causes Stiff Sore Feet And Ankle Pain With Burning Sensation?

I have had Plantar faciitis for over 6 months now..or at least that's what doc says it is..but have had more than just heel pain..wake up with stiff sore feet, occational arch and ankle paing, ocassional burning sensations, etc..just total foot pain..he ran some blood tests for arthritis and they came back negative. I'm very diligent in calf stretching, exercises, etc..but nothing seems to help..I have custom orthodics, dont walk around barefoot and have not run or played basketball since this started..The pain is probably a 4-5 out of 10 on worst days, so not debilitating. but is there every day..any advice?