No STD gives you the symptoms you're having. It could be balanitis, but it's interesting that your doctor doesn't see anything.
Don't use anything on it except a gentle soap or non-soap cleanser, or anything that isn't given to you by your doctor. There's no need to scrub it hard, or clean it too often - once a day is enough. Keep it dry.
If there's smegma, wipe that gently off.
I agree totally with GuitarRox - the ER is absolutely for emergencies - heart attacks, strokes, broken bones, loss of breathing, heavy bleeding, etc. It is NOT for STD testing.
(If you think you've been exposed to HIV and need PEP on the weekend, you can go to the ER. That's it. Anything else can wait. Oral sex is NOT an exposure to HIV.)
I don't know where you live but that was not worth an emergency room visit. That's a waste of emergency resources and costs more than what it should for this type of care. Find a clinic or doctor that will perform testing in the future. You didn't get a call back. Sure, you could call them but that they didn't call you indicates you had negative testing. You also so your own doctor. It does sound stress and anxiety related, to be honest.