Hello. I Have Flat Feet And Although I Know I

Hello. I have flat feet and although I know I should have worn better support footwear, I wore very flat sandals throughout our LONG summer. I have severe pain on the inside of my ankle possibly where the tendon supports the arch? I have swelling and constant pain. When I wear a wedge or heal it feels much better and the swelling decreases, which seems very odd. Walking barefoot is next to impossible. I guess I need an x-ray? What is this? I googled Gout but I don't think that's what I have. Thank you for your time.