I am in just that same diet boat now -- although my PF is nearly all better. But I have a good amount of weight I want to lose, due to sitting on my butt for nearly two years resting my feet.
I definitely agree with Nancy on bromelain. It has been a major factor in my improvement, and it is a non-prescription enzyme supplement you may want to try. You can search the message board and come up with tons of info on it.
I have not been as wildly successful losing weight with a low carb diet as the majority of people have -- but I continue with it because I really like how it makes me feel, and I HAVE lost a little. It has also definitely contributed to improvement in my feet. The better I feel and the better my feet get, the more seriously I can exercise. I am riding a bike (outdoor, not stationary) for exercise; fortunately it doesn't bother my feet and I think (hope) it's helping. At any rate, it's not hurting. Biking or swimming seem to be the top two exercises that show up here for PF victims.