On off the wall suggestion - if it doesn't work, at least it's cheap. I have high arches and about 7 years ago got plantar faciaitis (sp?) 6 months before a trip to China. After staying off my feet to let it heal I still ended up with cortisone shots. Got through the trip okay but for the next 5 years I lived in NothinZ - a Crocs knock off. I liked them better than Crocs, they seemed a little softer so they rose to meet my arch better, so soft on the heel... Crocs work too. However, neither one fits if you have narrow feet (I am a B or sometimes C width), and they are both ugly and not helped by the thermal socks I tend to wear them with. The ugly original syles actually work best, the new 'fashionable' ones have to thin a sole to really do the job. When I had to go out looking nice - these were not what I wore. NothinZ are hard to find in stores, Crocs are easier but both are available on line. (If Crocs don't fit, neither will NothingZ)
My diabetes was getting out of control at the time and I would tell people that NothinZ and Water aerobics literally saved my life.