Suggest Cure For A Not Appearing Near The Ear

Yes, i have a hard knot, pea or marble sized,in front of my ear. it is above my jaw, but if i open my mouth pretty wide, it seems to disappear behind the top of my jaw. It's pretty hard, but seems to change size. I have been experiencing a lot of aching and tension all over my head and neck, but when this knot is more apparent, the tension around my jaw, neck, and even into my right shoulder seems to increase. I do spend a lot of time on the computer and my sleep patterns have been increasingly erratic for various reasons.