Hello,
The symptoms are suggestive of allergic contact dermatitis or friction rub. Use mild soaps, wear cotton clothes and take some antihistaminic like Benadryl or Claritin. Also consult a dermatologist as you may need topical as well as oral steroids.
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.
Are you on birth control? Hormonal birth controls can put you at a higher risk for yeast infection, which might be explaining the swollen labia?
Are you experiencing any itchiness? If so, it might be a good idea to call your OB/GYN or your regular doctor and explain your symptoms and maybe they can call in a script for you.
Hope this helps!