My left side of my face sags. What can I do about this? (photo)

Dear KDavis1985,
Thank you for your question, and I am sorry to hear your facial issues are weighing you down. I recommend an in-person consultation with a facial plastic surgeon or plastic surgeon, as it is difficult to perform an assessment and provide recommendations based on photographs alone. The surgeon can discuss non-surgical options to help give you the restored appearance you are seeking. Filler injections alone, for example, can help turn up the corners of the mouth and give a lifted appearance to the lower face.  

You seems to have some facial asymmetry whereas your right cheek bone appears wider, lower and flatter than your left. This could account for the cheek sagging more prominently on your right than your left. Correction should be undertaken artistically not to compound the problem. I would to start propose adjusting the cheekbone discrepancies with a “liquid” approach such as Radiesse to improve the symmetry.Christian Drehsen, M.D.

No person has perfect facial symmetry.  For significant asymmetries you can try adding some filler.  I would suggest a hyaluronic acid such as Restylane or Juvederm which is reversible.