Pain between back teeth

[Kathy7752]

So I've been having this mild-moderate pain between the same two back teeth for about 6 months.  I went the dentist a few times, first he said that it seemed fine and the second time he said that my "bite was a little off" and fixed that.  He said there are no cavities.  I went home hoping that the pain would go away from the treatment he did, but it went away for a little while then came back worse.  I floss every other day and brush twice a day and use listerine.  The pain doesn't feel exactly like it's directly related to my teeth, but maybe more to my gums or nerves?  It's this gnawing, throbbing feeling that hurts worse whenever I eat/drink hot or cold things but all the time when chewing on that one side.  I guess I should mention that I grind my teeth when sleeping sometimes (but I guess not often or maybe I just don't notice it often) because I've woken up a few times from it(with jaw pain and headaches), but that was several months ago.  Another thing, the pain is worse at night for some reason- I woke up moaning in pain last night from it.  As I type this it's 1:00 am and hurts worse than it did earlier.... :/ I know nothing about teeth/gums/dentristy ahah

PS:  my gums on that side are not swollen but are slightly red

[Kathy7752]

And also... I forgot to add that my gums on that side are not swollen but are slightly red

[Kathy7752]

The pain does not get worse when tapping my teeth together...