I have a skinny face and i hate it. what should i do?

Perspective: I imagine that you are spending a fair amount of time thinking about this. Get some more perspective from others - talk to friends or other trusted people. Put it in a bigger picture - what are your positive qualities? Focusing on things you don't like about yourself tends to be self confirming - you are unhappy with yourself, others respond not to your skinny face but rather to your unhappiness.

Nothing: Your face will change with time. If you have a severe deformity, then make an appointment with a plastic surgeon, and preferably one who has completed a craniofacial fellowship.

Several options : A thin face may be related to underlying bone structure, atrophy (gradual loss) of soft tissue (eg fatty tissue, muscle) and the aging process where sagging tissues create a thinner, longer face. Soft tissue augmentation (structural fat grafting; cheek implants; filler injections) and/or lifting sagging tissues (face/neck lift) can effectively improve facial volume and overall appearance.

See a facial plastic: Surgeon for a full evaluation and recommendations. Without a picture it is hard to make specific recommendations. The answer depends on your appearance and the reason for your appearance. Do you have small bone structure or have your lost volume with the aging process? Cheek or chin implants might help, or other types of volume grafting like sculptra or fat transfer.