Suggest Remedy For Sore Vaginal Rashes

i have a rash on my vagina and there's a little bit swallon and its sore when i scratch.. I have very low self esteam so im too embarrased to actually go see a doctor in person. Im also 19 and had a baby girl in march she is my first child. Please help its really sore and itchy, it might be thrush but i dont know what that is? Xx