Oral Health Community

I am at my wits end and need some advice. On Oct 12 2012 I went in to have an old crown replaced (It wasn't done properly and I was having problems with it)-the tooth was not sensitive to hot or cold but it hurt to floss and there was a weak part toward the gum line when he touched it with an instrument. He cut off the old crown and put a temp on. I was fine for 3 days but on the 4th day I started having EXCRUTIATING pain in that tooth-I had to call in sick to work. I've never had that sort of pain in my life. I went in and he adjusted the bite, since I passed the tapping test and my X-rays looked fine. The pain continued-I was alternating IBU 8000 and Tylenol every 3-4 hours, and that only took the edge off of the pain. We rushed my permanent crown thinking it was the temp I was having problems with. Due to the severity of the pain we decided to move forward with a root canal, which was done Oct 23. He put the temp crown back on after the root canal, even though my permanent had already come in. I had normal sensitivity (brushing hurt, couldn't chew even soft foods on that side)-I had the bite adjusted 2 more times before he put the perm crown on WITH cement-when the temp crown was removed it hurt, felt like a lot of pressure. This bothered me but they assured me it was ok and there wasn't any nerve left. The perm crown continued to hurt-when I ate/drank something hot the tooth hurt to bite down on and would give me a dull ache. The ache/pain I was feeling was all concentrated in the tooth (best way I can describe it), it didn't feel like gum pain or anything. I've had the bite adjusted several times since Oct 23 (now 2 months later) but it still feels weak and achy. It doesn't hurt so much anymore when I bite, but when I bite ON something or brush I feel it. Even as I type it just feels weak. After all of that, it still hurts in the same spot when I floss. Not as I'm flossing down but as soon as I bring it UP I get a twinge of pain. How is this possible after a root canal? I wondered if it's a surrounding tooth but I feel every bit of the pain IN this particular tooth. The pain is very isolated to "inside" the crown. When I push on the outside of the tooth I feel like I can push the crown right off-if I bite something crunchy it hurts. I have been back to the dentist more times than I can count for this and I'm tired of the back and forth. He has done several x-rays and everything looks great with the root canal. I wondered if it was just tissue pain from all the trauma but after 2 months I don't think I should be feeling this sort of pain anymore. If there happened to be parts of the nerve still in it would I still have that excrutiating pain? Any idea what it could be? Can't go to another dentist without paying out of pocket. I love my dentist and I know he's doing what is best but I wonder if there's something he's missing? Thanks!
(PS: if this is not the right place for questions I'm sorry, this is my first time to post)