Originally Posted by 1stmolar

Background:
About a year and a half ago I developed a hole in my 1st upper molar. It was at the center and went thru the filling. I didn't think anything of it and I'd just floss food out after eating. A few months later I started to get pain. At one point it got bad but it eventually went down and just stayed at a level one could deal with. I remembered stories about tooth pain being the cause for many people's health problems, but I thought this little hole and mediocre pain was nothing to worry about.
The more I read and talked to people, the more I realized that there were many complications that could follow, including the abscess going into the brain. So I went to the dentist the first time about four months ago. He told me to get a root canal, or he could pull it, and put me on amoxicillin 500 mg, 3 times a day, for 5 or 7 days. After I finished the antibiotics, I went back to not doing anything about the tooth. Couple of months later, while flossing, a part of the tooth broke off. I start to get headaches, fatigued and dizziness the moment I wake up. I got to more reading and find out that the infection comes back if the root of it is still there, which is the tooth. Now, I start to get pain behind the eye and my ear. I decide back to the dentist, and he gives me the same story and puts me on amoxicillin 500mg again. 4 times a day, for 10 days. I finished those three weeks ago. Two weeks later, this past Monday, I got the tooth pulled by an oral surgeon. The next day, even though the numbness went down and the aftereffects of the surgery were staring to kick in, I felt ok for the first time in a long time.

Current situation:
The second day after the extraction I developed the kind of pain that I've only had once while the tooth was still in. This was much worse because that level of pain was there 24/7. Two days later I went back to the oral surgeon and he tells me that there is no dry socket, but that there might be an infection. So he puts me on amoxicillin 500mg, 3 times a day, for 7 days. After I asked, he tells me that the sores that I showed him are just canker sores that can be caused by anything. There were only a couple at the time.
As of now, it's been 6 days since the extraction and I'm on my fourth day of the antibiotics. The pain subsides at times but eventually gets back, sometimes to the level of the worst pain I've had there. I have two fistulas above my canine, which is three teeth down from the extraction site. I have one right above my 1st premolar. There is swelling around my 2nd premolar. When I bite down, there is still pressure pain at the teeth surrounding the extraction site. The sores inside of my mouth, across the gums with the fistulas, are spreading. My headache, ear and eye pain, are back, but on the other side this time. The lymph nodes under on the side of the extraction, under the jaw are painful to the touch.

What's my next step?

Am I right to think that the amoxicillin don't work for this infection anymore?

Before I pulled the tooth, I never had any fistulas, swelling, or persistent sores there. At the time, having read people dealing with puss, drainage, and swelling, it was just another reason I didn't think just my pain was urgent.
Having read some stuff on this site recently, I understand a few things weren't done right post surgery. There was no debridement done afterwards; I was given aftercare instructions and my tooth I asked for. Also, I wasn't put on antibiotics immediately after, even though the tooth was abscessed.
At this point, having read the helpful information here and looking at my nasty looking, decayed tooth, I understand that the bacteria is destroying the bone in my gums. Also, that it could be spreading to other parts of the body.

What should I ask of the dentist next time I see him?