My dog is spayed, but is still having a swollen vagina

Question
My dog was spayed last year, but she appears to have a swollen vagina and rash right now, which appears to be really bothering her, and she wont stop licking it, and is acting very lethargic.

Answer
If she is that swollen then she might have an infection in her vestibule area or a foreign body in there, like a sticker. One sticker can swell the whole area up and cause much redness.
The licking makes me think she is very sore there. I would have her looked at by the vet for a sticker, an infection or some other problem in that area or in her bladder. Even having a bladder infection can cause this although it is not common for it to do so.
You can give her a buffered aspirin to help until you can get her to the vets. Do NOT give her Tylenol, or ibuprofen, but just plain, buffered aspirin. Give her one per 60 lbs of weight.
Get her to the vet's then let me know what they found.