This sounds a lot like what I’ve been experiencing, I had a one night stand and studiedly took his word on being clean, I reacted almost immediately to that night there was tingling and itching. At first I thought it was a yeast infection, but the swelling and pain got to bad for it to be that, I looked down there so many times I never saw any bumps or sores (yet) it was just really swollen. When i saw the doctor though she looked down there and new what it was just by looking a bit, I’m now 7 days into my first OB and just now seeing spots, I started medication 3 days after symptoms started.
I’m not really sure If this helps you or not, but thought I would share my experience so far.