I would recommend trying to put the retainer set back in place. If you are having difficulty doing this without pain, it is best to put it in place at night, just before bed and then going to sleep. This helps for it to naturally just move into place during the night, as you sleep....
Unless you and your dentist have worked out something different, dental bonding is usually not included with your Invisalign costs. Every dentist is different, so it really depends on your specific case. In my office, dental bonding is billed separate because it is way more labor...
Based on your photo, I would caution against appliances to expand your upper and lower arches (jaws). Doing so can change the way your mouth feels significantly. You may speak differently (e.g., with a lisp or slur). I would definitely consider veneers. They are fast and...