Posterior tibial tendonitis-anybody have it?

I have been battling posterior tibial tendonitis in both feet for over a year. At least that's what I've been told it is. Basically it's pain on the inside of my foot below the ankle bone. I've been to two podiatrist, one orthopedist and three physical therapists. I've tried strengthening PT, resting PT and none of it's done any good. Usually swimming is a recommended exercise for people with feet problems like plantar fasciitis. Well, would you believe that swimming aggravates my feet. It appears the flexion of kicking and the pointed toe position of flutter kicking are what causes the aggravation. Basically I'm only good for about a half an hour before things start getting ugly. I can only pull so much without aggravating the tendonitis in my elbow. *** stroke is actually the least aggravating stroke. My feet are a set up for problems in that I pronate severely. Yes, I have custom orthotics-they haven't helped, in fact the problem in the one foot didn't start until after I'd gotten the new orthotics. Anybody ever have this? Anybody ever get rid of it? I'm really sick of this. I can't swim for a couple of weeks because of stitches (mole removal) but I'd like to get back in the swim of things after that. Thanks for any advice or sympathy. Jan