You should definitely go to a dentist for dental care. If the swelling has spread that far, it can be a very dangerous situation and requires immediate attention. If you can't see a dentist, definitely go to an ER and get it evaluated. Any time there is problems eating, swallowing or breathing in the neck area, it can spread further down into the neck and can be life threatening. You probably need to change antibiotics as well as it seems the penicillin isn't working. They can remove the tooth if possible. If not, they can drain the pus out of the area to help relieve some of that swelling and pressure.
CORRECTION! : I CANNOT OPEN MY MOUTH!
That is a big problem. Either go to your dentist or the hospital. The tooth, etc needs seeing too.
Yes, it does sound as though it is infected.
Prices will range between countries, etc. I live in New Zealand and it cost $300 to have two wisdom teeth out (just with normal local anesthetic).
The dentist or doctor will advise about the swelling.