CyclChyk - what kind of insoles are you wearing? If the ones your doc recommended aren't helping, you might be interested in the new Berry Superfeet, with the met button built in. (Orange is similar, but with a lower met button because it's pretty much intended for men's feet.) Some folks get huge relief just from wearing traditional Birkenstocks, too.

What kind of foot exercises are you doing?

Did the doc look at how your posture was effecting the weightbearing pattern on the foot? Are you doing deep hip rotator exercises? (to control the rotation of the femur/tibia so you don't weightbear too much to the medial side of the foot.)

What do the callousses on the bottom of your feet look like? Do you have a callous under the ball of your 2nd or 3rd toes? How about "whip" callousses, which are on the inside edge (medial/big toe side) of the big toe or ball of big toe?