My lips are asymmetrical when I smile, and my cheeks are uneven. What can I do about it?

Juvederm or Restylane would be a great option to help shape your lips, its temporary and usually lasts 8-12 months, Its best you seek a reputable, board certified medical provider and schedule an in-person consult for a thorough evaluation 

Pictures would definitely help, although an in-person assessment is most useful. Firstly, most people are actually asymmetric. Second, for a young person, a simple filler, sometimes with a little Botox, can actually reduce very nicely and safely the asymmetry.

I presume you have had a EMG of your face muscles to reflect no abnormal muscle pull.Are you symmetrical at rest?Need to arrive at a diagnosis before having a treatment plan. See a facial plastic surgeon and take all your results of the neurologist opinion with you to see whether fillers, Botox, or surgery might be possible.

I would love to help you, but cannot without more information. Can you post photos? Perhaps smiling, and at rest?