So you had unprotected sex. It doesnt matter if you think the partner was high or not, the fact of the matter is you had a risk.
6 days the right amount of time for chlamydia and gonorrhoea to show up. Dark urine isnt usually related to an STI.
The main thing is youve got tested. Best bet is to wait for the results and make a move then. It could be a simple UTI or an NSU which is easy sorted with antibiotics.
You had unprotected sex AGAIN after the last spiral you put yourself in by having unprotected sex? This is not a good idea. Get some condoms. You'll need a full std screening. Dark urine is from dehydration, most likely, so wouldn't worry about that. And discharge when masturbating? Hard to say. But IF you are suffering a discharge after unprotected sex, get checked. Usually they don't start until after a week after the event. So, yes, 6 days is a little fast but almost to that week to 3 week time period that many std's show up. But talk to your doctor.