Hi all, I'm hoping that you may be able to give me a little bit of direction here.

2 weeks ago I felt pain around my lower molar tooth - I visited the dentist and he said that I needed root canal therapy (which I have had before) and he completed the 1st stage that day. The pain in my mouth and jaw continued over the next week to the point where I was taking pain killers every 4 hours and was waking of a night because of the pain. (My next appointment with my dentist wasnt for 2 weeks). 8 days after I presented to the emergency room as I could feel a lump on my jaw and the pain is quite draining. The emergency room dr explained that he thought I 'may' have an absess from the tooth and he commenced me on amoxycillan, but told me I must see a dentist ASAP as doctors don't understand teeth!!
I couldnt get into 'my' dentist the following day, so I went to a new one who x-rayed my mouth and re-opened my root canal to redress it in case it was inflammed.

When he finished this he came to have a 'chat' and showed me the x-ray. At the bottom of the picture there is a sizeable 'mass' which he was concerned about, yet believes has nothing to do with the root canal. He asked me to obtain the 1st x'ray that my other dentist took to see if the mass presented on that, or if it was something new - but he said that he thought it was a solid mass and couldnt understand what could possibly cause it.
I rang my other (1st) dentist and spoke to a nurse who looked at the 1st x-ray and she said that there WAS something on it - she then had the dentist call me back and he said that there was something on there also, and that he really should have investigated further when I was there - but that at the time he was more concerned with the tooth.
I told him I wanted the x-ray - and he said no, and after arguing with him he then said that there was nothing to see on the x-ray.

??!?!?

My face is now numb from the middle of my chin up to the left side of my mouth.

I'm a 24 year old female, who has never smoked, but my father died of oral cancer 4 years ago. A tumour was found in his jaw and he was gone 6 months later. I really am lost as to where I should go or what I should do. I keep trying to tell myself that it's probably just from the root canal surgery, but I've got what happened to my dad in the back of my mind and I feel that theres something not right.

Do I have to go back to my dentist about this (I'm starting to lose faith in their knowledge), or can I go to a G.P - (even though the emergency room dr said that they 'don't do teeth'.

Any advise you could provide would be much appreciated - I don't think I can sit around waiting for another week and a half until I go back to my dentist.