I will be 50 years old with a severe class 3 crossbite. Please help! (Photo)

You need to see an orthodontist to evaluate your bite and give you options on how to correct your alignment.  It looks like you are a candidate for jaw surgery and alignment with braces.  
Good luck!

About half of my patients are adults.  On a scale of 1 being usual and 10 difficult, I rate your case 4.  After taking comprehensive records, my initial treatment  for you would begin with a removable expansion appliance on your upper teeth (8-10 months) and lower braces with elastics to correct your Class III relationship.  After achieving the expansion I would add braces to your upper teeth, detail and finish your treatment (10-12 months).