How to fix this extra mouth fat and double smile line? (Photo)

Treatments such as well placed fillers, radiofrequency treatments, and threading can help you with these problem areas. I suggest setting up a formal consultation with a board certified cosmetic dermatologist or facial plastic surgeon. Best, Dr. Emer. 

The heaviness you are seeing is called jowling, which also makes the prejowel sulcus peak deeper than it actually is (the area in the corner of the mouth just before the heaviness. Jowling usually comes with age but some people just naturally have it such as yourself. I would recommend internal radio frequency to the jowls or radio frequency miceoneesling and also some medium viscosity filler to help, such as Juvederm ultra. Hitting your concern from multiple angles, in my opinion, is the best way to get results. 

These lines are common and usually due to volume loss. They can be treated using a hyaluronic acid based filler. I prefer to used Restylane Refyne or Restylane Defyne when treating the lower face. 

The two smile lines that you're seeing are not related to the weight of your face. This is just the way the muscles are structured and your anatomy of the face presents itself. You can easily treat this with a use of something like Restylane which is a sturdier material than Juvederm. It should provide you with a good and natural looking result as long as you go to someone like a plastic surgeon who can treat you. Good luck from New York City