Vaginal bumps

I have a problem on my vaginal region. There is a slightly raised bump that’s tender to the touch right next to my clitoris. It has only been there for two days but I am a worried as this has never happened. It is itchy and painful. I am 15 and still a virgin so it can’t be any sexually transmitted disease. There hasn’t been any changes to my discharge other than it got a little more yellow and the smell is a little stronger, but I’m pretty sure that’s due to not drinking any water. Can someone help me about about what to do next and when to see a gynecologist? I’ve never been to one and I’m very nervous to go...