I just had a buccal fat removal, and one side of my face seems fine, but the other one is completely numb, is it normal?

Swelling, bruising and numbness of the face could happen right after buccal fat removal. The duration of the symptoms depends on the extend one the surgery and the type of local anesthesia used.
When lidocaine is used as local anesthesia, the numbness of the face could last up to 5 days. When marcaine, a long acting local anesthetic is used, the numbness could last for up to 24 hours. 

The buccal fat pad is near an area in the face that has many nerves and muscles. Depending on how recently you had the procedure, the problem you're describing could be from swelling or trauma to the adjacent structures.However, if the nerves were cut or cauterized, it's unlikely that the function will return. It's very important to continue close follow-up with your surgeon to see how things are coming along, so a decision can be made as to whether a surgical exploration and/or repair should be attempted.