See a dentist -- STAT!.
There is no quick way to "get rid of" swelling in your jaw. You can reduce the swellig a bit by taking Ibuprofen and applying a cold compress. But you must see a dentist right...
some swelling is normal. i am assuming that this was a lower tooth that was removed.
ice or a bag of frozen peas works well as an "ice pack" on the area. Please wrap the bag in a couple of paper...
many causees
most common dental infection after decay or periodontal disease
You should have it checked by a dentist. If there is no dental infection or periodontal disease, search on jaw clenching...