This remedy may be very hard to believe but the one thing that seemed to make a difference after trying everything under the Sun for many months was running itself. I put in a pair of Pinnacle Powerstep insoles and began running for about 10 mins., in plenty of pain. Within a week, I was up to about 40 min., still in some pain but much improved. I would say that within about 3 weeks, I was able to run as long as I wanted to which would be about 90 mins., slowly but I was actually running. The more I ran, the better I felt.
I mentioned this on another thread and someone commented that the insole was actually massaging the arch with every step and bringing in more blood cells to help in the healing.
The one thing I did not do was get a cortizone shot although that was suggested by my MD. I had read too many horror stories on LR about complications and bad results overall. Use the Search term on LR for lots more info on this subject. The risk/reward ratio was way out of whack as far as I could see.