sore lingual frenulum

For a few weeks now I have had mild soreness (only when attempting to stretch back the tongue or rubbing/"testing" sore spot with finger) on the lingual frenulum under my tongue.  It is an uneven surface, but there is no growth, redness, swelling, abnormal color, throbbing, or any other visible sign of irritation.  I am 23 and I smoke cigars (0-2 per day... so not much; and I've only been smoking them--off and on--for three or four years); however I'm thinking that the irritation may have begun when I recently began "chain smoking" a bit too much.  I have since cut back--and I have been swishing with Chlorhexadine Gluconate, though not entirely regularly.  

Could I be experiencing the residual of a canker sore, or some other tissue injury, such as a tear in the frenulum which is just taking a while to mend?  Could I have simply burned the inside of my mouth, and does area take longer to heal than others?

Thanks a lot for your input.

[Mitch81]

I have the same problem only I chew snuff but I check my mouth regularly and have had my mouth checked by doctors and dentists and they all say it is fine. IT looks completely normal but every once and while when I stretch my tongue backward in my mouth it feels a little tender. I work in a hospital and have been told by doctors that I irritate it by stretching it and feeling it with my fingers and if I would leave it alone and quit obsessing about it then it would go away. If you have had any other opinions on it please let me no.