Hello and thank you for your question.
First, if you are allergic to seafood it is best to avoid it because you may develop a more
severe allergy and cause yourself to go into anaphylatic
shock that can kill you.
Second, you should use crab leg crackers not your teeth to break open hard items. Teeth are meant for chewing, not for an opening tool. This is especially important to follow if you can't afford dental treatment.
More than likely there is not crab in your mouth still after a month unless you have not been flossing your teeth. Then possibly you have a piece of crab stuck between your teeth. The culprit of the swelling is most likely the tooth. If you are having throat pain, an awful taste in your mouth and a
swollen tongue, you more than likely have a dental infection such as an
abscess. It is best addressed by a
dentist. If you have an infection it is a good idea to get it treated. From the sounds of its location you could put yourself at risk of acquiring a more deadly infection called ludwings
angina which is an infection of the spaces between the bones, muscles and ligaments in your throat. Basically the infection swells your throat shut and makes you look like a bullfrog. Dental infections should be addressed as soon as possible.
You may want to find a free dental clinic in your area under google, or find a dental school near you which has discounted prices. If you have medicaide, medicare, you can go to a dental school get an x-ray, exam and extraction for about $3 copay.
I hope this helps.
Best wishes and good health
Dr. Ward