Hello,
it looks like you had frictional
injury that got worse due to secondary infection and the white little spots may be pustules, and that might be the reason you are getting
fever too.
Apply warm compresses (cloth soaked in warm water, not too hot) over the area
and take a course of
oral antibiotics like
ciprofloxacin 500 mg twice a day for 5 days or amoxyclav once a day.
Take
ibuprofen for the pain.
Another explanation is bartholinitis, infection of a gland located in vagina, in which case you must consider consulting a gynecologist.
Thank you, hope I helped. Feel free to follow up in case of doubt.