well I haven't had a problem since I stopped wearing those types of shoes. It was funny, I had just bought 3 new pairs of slip on backless shoes and was wearing them for a couple weeks when it started. In fact I wore them to the foot doctor. After he heard my complaint and checked it out he pointed to the shoes and said "there's your problem".....
I said oh no

I just bought 3 new pairs! Oh well I'm careful now to not wear anything that I need to grip.....If I wear sandles, they have a back to them, but I'm more comfortable in gymshoes or sketchers anyway....
now it's comfort over style for me! I hope your new shoes work for you.....what kind of shoes were you wearing before when you say it happened overnight?