Bump on Vagina opening

So I just discovered a bumpy ridge thing on the opening of my vagina, I don’t know what it looks like because its literally right in the opening but I can feel it? Upon contact with water or urine it stings but if I just touch it, no pain. There was a smell coming from my vagina but it doesn’t smell fishy, maybe like soy sauce? I really can’t describe it! I’ve had little to no discharge that’s white. Recently I’ve been taking an antibiotic Clindamycin for an infection but this antibiotic basically fights everything, it treats UTIs, infections, etc so I’m wondering if its a flare up? Or something, idk I’m a little confused. I’m not sexually active so it can’t be a STI, and if it’s a bacterial infection or UTI, wouldn’t it be taken care of from my antibiotics?