Never Ending Root Canal Nightmare

3 years ago: I had a large cavity filled in a front tooth.
1 1/2 years ago: Same tooth starts to hurt. He takes a look, and says it's definitely the same tooth.  He suggests that he may have hit or killed a nerve during all of the filing/grinding, and tells me the pain I'm experiencing is my tooth literally dying. He sends me home with antibiotics to clear up the infection.  A week later, I return for my first (and hopefully last) root canal.  No crown. I'm given more antibiotics when I leave.
Two weeks later, I call the dentist.  The tooth still hurts, and it has a strange odor.  He tells me to be patient, and that it is possible to feel some pain weeks or even months after a root canal. He calls in another prescription for antibiotics.  Two days after I start taking them, the odor goes away.  Four days after the prescription is gone, it comes back.

I make an appointment to see him again. I ask him to PLEASE look at it, and I'm starting to lose my patience.He takes an x-ray, shows me the image, says the root canal was successful.  He decides to grind one of my lower teeth down, suggesting that the pain might be caused by the way the two teeth hit when I close my jaw.
8 months ago: Odor hits a level of gross I wouldn't wish on my worst enemy.  This isn't a flossing/brushing/tongue scraping/antiseptic rinsing issue.  I do this several times daily to get rid of odor, and it returns within five minutes every time.  I stop using mouthwash with alcohol, after I realize it intensifies the smell.  I start seeing new dentists.  I tell them the story, they take an x-ray, say the root canal is just fine, and send me on my way.  

Yesterday: I saw my 6th dentist in 8 months.  This has been going on FOR YEARS. The smell of this tooth affects my quality of life.  

I can't get anyone to listen, or take this seriously. I don't want to have a dangerous infection spreading in my mouth/jaw/bloodstream/etc, and don't want to lose my tooth. Any advice would be REALLY helpful.

[Jerome Tsang, DDS]

Have you considered going to a root canal specialist?  You may want to get the root canal done again possibly.  I'm not sure why its giving off an odor though.