As you can see, one side of my face is bigger or fatter than the other side. Please tell me what to do. It's really odd (Photo)

 Nobody has a completely symmetrical face. When he perfectly symmetrical face is created by  computer imaging it is less attractive than the same face of minor asymmetries. There's nothing I see and provided photograph it is worthy of  Treatment.

Your facial asymmetry is quite minor in my eye, judging by the photos provided.  However, even small asymmetries can be bothersome and a closer evaluation by a surgeon would be of more benefit.  That being said, it appears to me that removing the fat pocket (buccal fat) inside the left cheek would do wonders to correct most or all of your problem.  This is a 20-30 minute procedure done through tiny incisions inside the mouth and can be performed under local anesthesia.  I frequently perform this procedure during facelift surgery in full faced individuals in order to create a slightly thinner, more sculptured look.  The results are very subtle, but very pleasing in the right patients.