Sounds like thin tissues in the vulva region. Get some sudacrem or similar on the area now and later in the day.
As oestrogen levels drop the skin may become dry/thin. Itchy, sore, red; between the toes, vagina, anus, scalp, deep in the ears etc.. Appropriate vaginal atrophy treatment will ease symptoms.
One could ask for 'vagifem' to use internally with 'ovestin' gently applied to the vagina and perineum to keep the skin softer and less likely to split.