I need help!!

Okay so lately everything down there has not been going so well. Btw I'm a very clean person I usually take like two showers a day and only clean down there with water unless I'm ganna have sex then I use like alittle Summers <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a> just so things are extra nice. Lately tho I've been smelling off and so in the shower I did alittle internal searching, I thought maybe there was a broken condom piece or something like that but nothing except for a tiny bit of a cottage cheese looking substance and it terrified me. Last time I had sex was in august and I was fine after that. Do I have like an sti or something.

I'm 17 btw and I don't have an obgyn, my dad thinks if I go to one it's Because I have sex....he doesn't know I'm not a virgin so idk what to do...please help me