Hi. Thanks for the query.. Sore throat, swollen lymph nodes along with swelling inside the mouth seems most probably be due to Pericoronotis that is inflammation of gum flap if you have an impacted or erupting wisdom tooth.. Pericoronitis also leads to inflammation and soreness of throat and tonsils as well as swollen lymph nodes as well as pain and difficulty in mouth opening.. You should consult an Oral Physician and get evaluated and a clinical evaluation and x ray can help in diagnosis and initially the physician can advise you to take antibiotics, anti-inflammatory painkiller like Ibuprofen and do warm saline gargles and take a soft diet.. Do warm compresses over the lymph nodes.. Once swelling is reduced either extraction or removal of gum flap can provide permanent solution.. Hope this helps.. Regards.