The reason we change your wires to thicker ones is because as they move up in size, they continue to straighten your teeth. You will eventually get into a wire that your orthodontist will bend himself to move certain teeth into different positions. You should only be sore for a couple of days and then you'll be back to normal. I'm in braces for the second time and I work as an Orthodontic Assistant so I know exactly what you're going through. I sure do get tired of eating soft foods haha!