Hi,
I can understand your difficulty. You have a slight itch and burning sensation over the vaginal opening or 'introitus' as it is called. This can happen due to rough intercourse when the lining epithelium gets damaged, when there is an infection of the vagina or the urethra, due to use of tight and unhygienic undergarments and poor genital hygiene. Please see a specialist for a clinical evaluation and a swab test to see if there is any infection. A urinalysis helps to exclude urinary infection. Avoid wearing tight underwear and maintain genital hygiene. Use sanitary napkins instead of tampons and avoid intercourse until you get relief. Hope this helps.