I've had the same problem. Buy some good fitting walking/jogging shoes (I find them at Walmart for about 28$) with built in arch supports. Then stand about a foot and a half from a wall and put the toes of one foot against the wall with your heel still on the floor. Place both hands on the wall and gently rock up onto the toes of the other foot. You should really feel it in the back of your leg. Do it several times, several times a day, switching feet every 5 or so times. This simple exercise will help lengthen the tendons in the back of your leg. Shortening of that tendon is what causes arches to fall. You can ask your orthopedic doctor about it or look in up on the internet. It worked for me but it's not an over night fix. I went 2 years without going barefoot. I even had to put rolled wash cloths under my arches in the shower. Oh, and NEVER wear high heels---even short ones. To this day I never wear shoes without arch supports but I am able to go barefoot in the house again. If you have wide feet like me, go to the men's tennis shoes. They look the same as a lot of the women's but they're 1/4-3/16" wider. Just go down a size and a half or two sizes. I wear a 10 in womens but an 8 in mens.