This could be a boil. Your drugstore has an ointment for this, ask your pharmacist hope you are better soon.
Most probably it is foliculitis that is inflammation of hair follicles. Usually it is due to bacterial infection. Apply local antibiotic for 2-3 days. The other possibility is the inward growth of hair called ingrown hair. For this, first remove the hair and then use antibiotics.
This is very likely just an inflamed hair follicle. If you shave in that area it may be what is often called an "ingrown hair". Applying a cortisone/antibacterial cream will help the inflammation and encourage it to heal. If you're shaving the area, always keep it well moisturized with a good quality body lotion. Hope you get some relief.