I have a tooth with small silver filling and it hurts so bad like if the nerve were exposed what could be the cause of this suddensharp pain?
There are a few possibilities
You could have some decay under the silver filling, which would cause pain
You could have a fracture in the tooth which would cause pain
The cavity could be near the nerve which would cause pain.
Get to your dentist and have an exam and xray to see the exact cause, the sooner you go, the smaller the problem.