Dentist question/root canal/filling

So I got a cavity filled and it was a super deep cavity. She said it may be painful for a few days. That passed... 2 months later I got really bad pain where the filling it. It was throbbing, etc. She has me come in because she assumed id need a root canal. I was in severe freaking throbbing pain for 3 days before I was able to get in. Im not one to take pills. I didnt even take pain pills after a 3 incision surgey i got. I can handle alot of pain before caving for meds. Anyway- Ive been popping Ibuprofen 800s mixed w tylenol for days now with out ANY relief. Normally i can take the lowest dose cut in half and im healed lol. At my appt she said nothing bad showed on xray. She filed my filling down because she said she thinks its irritating it and causing the pain from my bottom tooth rubbing it and pounding on it everytime I eat. So I left. Its day 2 and im still in pain however the ibuprofen is finally giving me relief. Is this normal? Do you think the pain will go away? She said it could take 48 hrs before pain disappears because it wad such a deep cavity.