hello thanks for the consult at hcm.. It could be lock jaw involving tmj..it belongs to tmj disorders.. Do you have the habit of night grinding?? Did you have a recent cough and cold, since your lymph node is swollen behind the ear?? Regarding treatment for that lock jaw and popping, give rest to the tmj.. Avoid eating hard food.. For night grinding habit, you could get a night guard.. Take treatment for cough and cold with medicines such as antibiotics and analgesics.. Kindly consult a oral physician for a check up and treatment..also visit a tmj clinic in your area.. Hope it helps..take care...