I had similar symptoms, and found out everyone in my family has this same problem! It seems to be degenerative too - will only get worse over time. The pain started with heel pain, but got to the point where it would hurt to get out of bed in the morning, or to get moving after sitting at my desk for a while.
I recommend 2 things: Go to a podiatrist or the "Good Feet" store. There's one in Fargo even. Their inserts are expensive, but they never wear out, and can go in a variety of shoes - maybe not sandals, but they work in loafers, sneakers, even shoes that have a little bit of a heel. I do find that I like to try shoes on with my inserts, and I look for shoes that have a fairly high back, since the inserts lift your foot up a little in the shoe. DSW offers enough variety that I'm usually able to find something cute enough but works with my inserts. If the inserts still feel strange, take out the factory-installed insert out of the shoes you buy (which have ZERO arch support), and replace it with the insert from Good Feet.
Second, For walking, go to a specialized running store for a tennis shoe fitting. In Fargo, I recommend the Fargo Running Company. They'll take an imprint of your foot as you walk, and they'll watch you walk to analyze how much stability & arch support you need, and they'll recommend a shoe. I like the Brooks "Ariel" shoe. I don't use my insoles with these shoes but my feet don't hurt anymore.
After doing these 2 things, I find that I don't have to wear my insoles every day, and can wear heels every once in a while. When my feet start to hurt again, I go back to the insert and tennis shoes every day "therapy".