It can be a swollen lymph node, infected hair follicle or infected sebaceous cyst. Apply warm compresses and some antibiotic cream like Nupirocin or Bactroban and keep the area clean. If the symptoms persist or worsen, then you may need a course of antibiotics, FNAC test or surgical drainage of the lump. Please consult a dermatologist then.
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 dermatologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.