What's wrong down there???

Okay so for a long time I've been quite itchy down there. I've also noticed that I have some kind of 'residue' that I swear reminds me of toilet paper. I don't think it is because even after washing I find it comes back quickly. I'm getting really self conscious about it and very frustrated with the itchiness. As in I've had these for a really long time it didn't come up after something specific that I can think of. It might be worth mentioning that I'm not sexually active, I'm very clean and I started using summers <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a> not too long ago. Nothing's changed since I started using it. If you have any advice on what it could be, especially that weird residue thing it would be of great help :)