Undesirable place

Lasting continuous pain on lower right first molar prevents me from doing anything even spending good time with my lovely friends. This kind of pain is, some time sharp and another dull and continuous, so to speak bad settlement.
I determined myself to knock some Dentist's tomorrow, asking to remove all the bad tissue inside of the tooth and to clean all of the residual wall there killing out all kind of bacteria, to fill in the holes to the end of root tip not to enter any tissue liquid inside again that would cause secondary infection. Finally, it would be fulfilled with metal inlay again taking time about 1 month from now.
Wanna I ask you all that why the gate of the Dentist is so huge and so heavily dark like a prison?