Vaginal irritation??

Every now and then one area of my vagina always gets super red and swollen and my discharge also becomes really really watery. It’s always the inside of the left lip and it’s always in the same place but I can’t figure out what it is!! It is just really red and irritated! I’ve been tested for STDs and I got o my gyn frequently because I’m scared of STIs but she doesn’t seem to think I have any. I am absolutely terrified of herpes and it’s my worst fear so I constantly go and get checked by a gyn but I’ve never had a blood test for it because it is very expensive.  I haven’t gotten this looked at yet but it is just a really big red spot on the inside of my vaginal lip! Whenever it comes around I usually ignore it but it’s been so uncomfortable lately idk what to do. I’ve struggled with BV in the past but I just got rid of it and I tested negative for BV last week so I doubt I have it again! Anyone have any idea?

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