Why wont the dentist treat my nerve? will i lose my tooth?

I have had a similar problem but in my case i think it was my dentists fault for not doing a good job of the filling in my bad tooth in the first place.i was awake watching tv at 3am monday and i was eating some toast and my filling came loose inside the tooth.I went to the dentist at 9am the same day and unfortunatly my tooth was rotten underneath so i had to have it pulled,and it hurts like a ***** still.I suggest u ring your dentist and tell em u are in severe pain which is causing you to be unable to eat or sleep,any good dentist surgery will see you the same day as u phone,that way u are not waiting 2wks