From your symptoms, chances are more likely that it is a swollen lymph node because it is close to the site of bite. For swollen lymph nodes, we think about the simple possibilities first and then move on to higher ones like cancers.
Treatment includes warm compresses, over the counter anti-inflammatory analgesics(pain killers) like acetaminophen or ibuprofen, antibiotics if cause of infection is suspected to be a bacteria and surgical drainage if there is any abscess formation.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.