Removing mercury can give you flu-like symptoms.  Hopefully no mercury was left, but some dentists do, so you need to make sure you go to a Biologic Dentist when you get mercury fillings replaced.  You can have one check it later, metals will show up on x-ray. 

What you are describing can be symptoms of mercury poisoning from drilling a filling out.  You should get fillings taken out by a biologic dentist who cuts then out and uses proper protocol (Huggins' Protocol is best).  Mercury is very volatile, it goes everywhere.  The last mercury filling I had, half my body went numb.  I know a Congresswoman from Mcminnville Oregon who had 4 mercury fillings done and half her face went numb and she had to go have them replaced with white (there was even a write up in the Statesman Journal newspaper about it);  Mercury is nothing to mess around with.

The antibiotics for your tooth are most likely not needed, because it takes 5 days for infection to set in if you were going to get an infection in it.

If you have pain in that tooth, then it may need to be replaced by a temporary medicated filling or the tooth may end up dying.  Very large fillings sometimes do that because they get too close to the pulp chamber.  Sometimes the nerve will get irritated, but calm down on it's own.  So, let's hope for the best.  Yes, the gum can be torn up a bit, because of the procedure, but should go back to normal soon.  Use Amosan oral wound cleanser.  You can find it at most drugs stores.

Some people have reactions to white fillings also, so best to get a biocompatibility test to make sure the materials are the least toxic for your body. 

Torrie