If i suspect an abscess near a recent filling how long can i remain healthy until i can make an appointment?

Visit dentist now: A dental abscess develops relatively quickly and therefore needs either antibiotics or drainage of the dental abscess as soon as possible. If you are unable to visit your dentist soon, visit a doctor to get a script for antibiotics within the next 24 hrs.

Earlier the better: You should see your dentist soon. if you are not in much pain then you can wait till you can see a dentist. if you have severe pain you can get some help at an ER to relieve the pain somewhat till you see a dentist. Either way a dentist is what you need ultimately.