Hii , Welcome To HCM & Thanks For Asking Your Query Here
I have gone through Your query and will try to provide information you need on it
from the medical history you provided it seems like you have a vaginal
abscess more specifically it may be a Bartholin's Abscess
it can occur when Bartholin’s glands, located on either side of the opening of the vagina, becomes infected
It’s common for this to cause pain during any activity that puts pressure on the area, such as walking, sitting down, or sexual intercourse.
A
fever may also accompany the abscess.
i will strongly advise you to stop
self medication and self treatment and immediately contact your Gynecologist, he will perform a physical examination to check for any lumps within the vagina that would indicate an abscess. They may take a sample from the area to check for any STDs. (as you said u already had an STD before ) Those STDs would need to be treated along with the abscess.
If you are over the age of 40 or have already gone through
menopause, your doctor may want to perform a
biopsy on any masses found in the vagina to rule out other sources of the problem
however it may be variety of other medical conditions and seriously it needs thorough medical check up and investigations to spot a confirm diagnosis
I hope it help
Thanks & Get well Soon