I found a new flip flop too. Their called glitterflops. I've had four surgeries on my left foot, so deal with a lot of foot discomfort. These are the most comfortable shoes I've ever worn. I believe they are made with memory foam. They are very pricey though, probably because they are also made with Swarovski crystals. If any of the crystals come off, they replace them free of charge.
If your flip flops are less expensive, I need to look into them.