Help😫

I've only had sex once (last weekend) and it was unprotected but I've been fine, and now a week later nothing has been unnormal until I wore this thong, as soon as I took it off I started itching, this was Friday. It's now Sunday and my vagina is sore there's sometimes a smell but it's normal and I have no discharge(what does this sound like) I'm 17 and I can't just tell my mom I'm active, I really wanna see a gyno but idk how to ask should I just tell her about the thong? or is there a clinic that I can go to by myself and she won't find out?Â