There are two possible causes for this lesion:
1. Folliculitis: infection of the hair follicle as you have been having. For this, use a hair remover to remove hair rather than shave, try to pull out the hair root with a forcep if visible and possible, keep the area dry, change your undergarments twice daily and wash them with hot water and detergent. Hot compresses are very helpful and apply some betadine
lotion after extracting the pus, or clean with savlon
after extracting the pus and let dry and then put neosporin
powder. This must be done twice daily till very little pus comes and then just clean with antiseptic and apply neosporin. Get a blood sugar test as raised sugars may cause repeated infections.
2. Bartholinitis: infection of the bartholins gland that lies in that area. Similar measure like above will help control the acute phase of the disease but if it is recurrent it will need to be removed surgically.
I hope this was helpful. Thanks for using HCM.