How much would it cost to enlarge my jaw, and how many day would it take to recover?

Plastic surgery: not usually covered so cash costs are probably in the 20 k range

Depends: You need to consult with an Oral-maxillary Surgeon and Dentist to determine the exact procedure, professional fees, hospital fees and post-surgical care involved in your case. Recovery time can vary. You will have additional restrictions in driving/operating machinery/or work while you are recovering, which must be considered in the "cost".