I have a sour-like taste in my jaw as if i was eating sour candies or sucking on a lemon. could this be a salivary gland issue or something else?

Sucking a lemon: It very well could be a salivary issue. I would see your dr asap to determine if there is a problem.

GERD: It could be a salivary gland problem but it could also be something else. Do you have swelling or pain around the salivary glands? Acid reflux or gerd can cause a sour taste in your mouth. The best thing to do is get this checked. Start with your dentist or oral surgeon.

Something else: It could be a number of dental and\or medical problems and would have to be checked out by both your dentist and physician to determine the cause. Make some appointments get some accurate answers and to resolve this issue.