Dear Alexis, You don't have a true sagging skin but rather an inadequate volume at the mid cheeks, nasolabial folds and below corners of the mouth. If you are looking for a long lasting result I would go for fat or fat stem cell transfer or permanent filler.
You definitely do not need a facelift at age 19. There are options such as radio frequency treatments to help tighten the skin or augmentation of the nasolabial folds with either fillers or fat. You should consult with an American Board of Plastic Surgery certified plastic surgeon to discuss your concerns and options.
Your face is still changing to an extent. From your photos (an exam would also be required) it would seem that fillers may benefit your appearance. If you like the appearance then you might consider fat transfer in the future for a more permanent effect.
Based on your limited photos, I would expect your concerns could be addressed with injectable fillers. An in-person consultation would be required to formulate a detailed plan.
You don't need a facelift. However a moderate amount of volume added to your cheeks would make a huge improvement. I probably would use Voluma. See an experienced injector.
I would definitely not recommend a facelift for you at age 19. From the pictures you provided, it does appear that there are some areas of your mid face that could have volume added with injectable fillers. This would improve the nasolabial folds and lead to a more youthful appearance.
I'm really not certain I would do anything but a small amount of filler in the nasolabial fold and possibly the cheek area would give modest but meaningful aesthetic benefit.
You don't need a facelift, but adding volume to your cheeks would be a huge improvement. You can do this temporarily with filler and if you like it do it more permanently with fat grafting. Falling of your face is not your problem as much as your face needs volume, especially your cheeks.
Stephen M. Davis, MD, FACS
Green Hills Plastic Surgery