Hello,
This swelling can be due to chafing. Chafing occurs when the skin becomes irritated by the friction caused by rubbing – either against other skin or against a foreign material. Wash the areas several times with fresh water. Do not use any cosmetic products at the sites. You can apply some calamine lotion at the rash as it will help in soothing the skin.Also wear cotton undergarments. Application of mild corticosteroid cream and oral antiinflammatories like ibuprofen/acetaminophen are also helpful. If the symptoms are severe then it will be best to consult a gynecologist.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing
It sounds like you have a vaginal infection. Sometimes the natural yeast or natural bacteria (or introduced bacteria) grow out of control and cause symptoms you describe- swelling, ichiniess, burning, lots of discharge, abnormal smell, odd colored discharged, etc. You don't need all these symptoms to get an infection and you certainly don't have to be sexually active. I suggest talking to your mom or parent if you're under 16 and seeing the dr. The dr will tell you if it's a bacterial or yeast infection and then how best to treat it.