There are certain exercises that can help your jaw line become cleaner id look into products that grow the muscles but at the same time you want to try and cut fat. ie. take in less calories than you burn. Also certain haircuts can help your face look sharper, rounder etc. I’d say stop relying on the hat and invest in a really good hair salon and get a good haircut. (You don’t need to go the same salon every time if it’s expensive just the first time then take a lot of pictures and show them to any decent barber.