Ok so I got my size, and they felt ok in the store but now that I'm wearing them around the house they're hurting the side of my foot(the inside side) a little. I have really flat feet - I didn't use to but wearing flip flops so much made my arches fall. Should I have tried to find a wider shoe? It was hard enough to find shoes in my size that were comfortable and not too expensive. The box says they're medium width, they fit fine but when I stand up my feet flaten out so my foot is wider than the shoe and kind of hangs over.
My question I guess is will I just get used to the way they feel? I had to drive an hour to go get these shoes and I really can't afford to go back again any time soon.
Also I have tried on wide shoes before and my feet slipped around in them a lot - maybe because my feet weren't wide to begin with it's just my fallen arches that are causing the problem. 
I wish I could go back in time and not wear flip flops on all those long walks. 