You certainly have had a good deal of conservative treatment for your problem. One thing that you did not mention was injection of cortisone. At the risk of sounding like a broken record, as I seem to write for most of these responses, I would know a lot more if I examined you. However, if I had done all these treatments, and we were not getting anywhere, then I would discuss surgery. If I was not sure about the diagnosis, I might consider other potential causes of heel pain, such as a bursitis, tarsal tunnel syndrome, stress fracture, and even referred pain from the low back. These are just a few of the other things that we see in the heel area.
To see is to know, not to see is to guess.