Anytime you get a new swollen bump that is painful, it should be evaluated by a physician as early as possible. Swollen lymph nodes are usually a sign of infection which may need to be treated with an antibiotic depending on the cause. A swelling under the jawline can be one of several things. A lymph node is certainly possible and if you've felt a little under the weather lately, it could be a lymph node fighting an infection. Also in that area are salivary glands that make saliva for our mouth. These can also get infected and be puffy and swollen. Without some obvious trauma to the area, it would be very unusual for a lymph nod to burst. They are surround by tough capsule and are not under any significant pressure to allow for them to burst. Its still possible, but its much more likely that you have some soft tissue inflammation that got worse overnight. I would schedule an appointment with your primary care physician
as soon as possible to get your neck looked at. If you develop any additional symptoms (fever
, night sweats, pain while chewing etc), you should be seen right away. Good luck.