Sherry, the flip flops could be the problem. They are about the worst shoes for your feet. There is no support for the muscles, tendons, and ligaments, and also you have to scrunch up your toes to keep them on your feet when walking.
You could find sandals that accomodate the bunions. The Birkenstocks that I love are the Arizona model...they were a favorite of the hippies! LOL They have two wide straps. The one that would go over the bunion area can be looser. You can adjust both straps. But the arch support and heel cups in these support your feet. They do need time to get used to, if you do buy a pair. It took me about a month to get used to them because they make you walk properly. I only wore them for a few hours a day at first. Now, I can walk all over the place with no foot pain. They also cleared up my plantar faciitis....that's why I bought them in the first place.
Sherrine