I have a hole in my tooth why will happen.

So I’ve got a hole in my tooth and I’ve filled it with temporary filling for a couple of months now and when I eat something and it pushes the filling to the gums and it starts to hurt with a sharp pain. Which causes me to add move filling to stop the pain cuz if the hole is exposed it hurts then touched. What will they do filling or a crown cap. Plus now I’m over 18 I have to pay for my treatment.