What temp is it at right now? And have you tried giving it a good stir with a sanitized spoon/paddle? Sometimes all it takes is to warm it up a couple degrees and rouse the yeast again to kick them back into gear. So I'd try that before repitching. You do have a very high gravity to start with so it isn't likely to finish very low. In fact, a typical yeast that attenuates around 70-75% will likely only get you down to about the 1.040 range anyway. So there's a good chance your yeast have done all they can do.
I'm not sure what your recipe is or anything, but if it's something like a big RIS it's usually going to finish pretty high. My RIS started out around 1.106 and finished perfectly at 1.028. Plugging wyeast 1084 into my recipe and boosting it to 1.120 OG it estimates a FG of 1.038. So it seems like you are pretty much on target. If you try to get it too much lower it could end up too dry for having that much alcohol.