I Have Had Pain For One Year In Heel. I

I have had pain for one year in heel. I have tried anti inflammatory meds, massage, ultrasound, ice, splinting, kinesiotaping, and cortisone shots x2. I still have pain. I have treated it as Plantar fasciitis. My Achilles is not tight. X-ray ruled out bone spur. I have an MRI scheduled in two weeks. Any thoughts on cause of pain (which is an 8/10). I'm out of ideas.