Fins, here's what you do. And stop blindly buying shoes and inserts, every foot is different. I have two pair of the following...
[Link: footlevelers.com] Find a local Chiropractor that carries these, they are awesome and will, odds are, fix your PF. Mine run about $275 a set. I go into my guy (via my BNI group), he has a foot scanner, ya just stand on it like a scale, and they get what they need. Pick them up a week later.
Also while you set up this relationship you should have the Chiro do a couple xrays to take a look. Top to bottom, it's all connected.
Last, pick up one of these, or similar...
[Link: stabilitypro.com] They keep things stretched out while you're sleeping.