Hi welcome to Health care magic forum. As you look it is abnormal, and troubling you, leave about the reasons , you are expected to see a doctor for relief.
The reason might be allergy
or infection, allergy might be due to contact of some allergen like rings etc. Infection could be due to injury
like prick, or with out any reason.
Besides i advise you some diet recommendations as avoid taking pulses, fissh, and potato as these tend to increase the pus. If it is infection it need to be drained by a surgeon.
avoid taking sea foods and brinjal as these may tend to increase the allergy.
Wishing for a quick recovery and thanks for calling.