Hi, I'm On Here To Ask A Very Important Question

Hi, I'm on here to ask a very important question regarding my health. I am a 16 year old girl, who is sexually active and noticed that a month and a half after having sex for the first time, my labia has this white toilet paper skin on it. It's been going on for about 3 months now and each time I clean it, it comes back. I've also noticed that when I'm on my period, it doesn't make the white toilet paper skin as much because I use tampons which absorbs my discharge. So I assume it's my discharge making my labia that way. I tried cleaning my labia with a mixture of water and white vinegar, but it no longer works. Do you have any idea what it could be? I can't go to the gyno because it costs a lot and I can't let my mom know I'm sexually active either. If someone can help me out, I'd appreciate it greatly.