Greetings. ! As per your description of your problems i can say that you need to get yourself examined in detail. You seem to have a Temporomandibular Joint (TMJ) issue. I advise you to consult a Specialist ( Maxillofacial Surgeon or Oral Medicine) who come across such problems much frequently and would further guide you as per your clinical findings after checkup. You also have infection that needs a check at the earliest so as to avoid deterioration of the same. We would be very happy to help you. Regards, from Health Cottage Hospital. GOOD LUCK.
This might have happened due to lymph node enlargement. Better to consult a dentist so that the cause can be ruled out and appropriate medicine will be advised so that the swelling will be reduced as soon as possible and you will be able to open your mouth with out any difficulty.
Luke warm water with salt gargle might help you a bit.
Visit a Physian to rule out any general problem and once that ruled out, visit a Orthodontist for a TMJ examination. They will prescribe you with a CBCT or a MRI scan. They they will fabricate a splint if tmj is the problem..
Limited mouth opening in your case could be correlated to wisdom tooth eruption especially since you mention painful lymph node, it is indicative of some infection. Please meet a dentist to rule out dental cause before meeting a physician