rashes, throat problems and burning vagina

I recently observed about 10 rashes at different locations of my body. namely: neck, thigh, arms and was wondering what could cause this? they are dark and will get white if not medicated. i visited the doctor who prescribed a cream but did not say what caused them. i am now having a problem getting rid of them.
i also have a throat problem where it feels as if i am forcing to talk and it hurts real bad. i am a teacher and when i talk it hurts and it feels like my throat is being blocked off by soemthing. Another problem is that whenever i have sex after the intercourse there is a burning sensation and sometimes my vagina gets all swollen and itches for a week or so. what could cause this?
Thank you for your time.