I'd say it is the anxiety, working on CBT worksheets easily found online helped me work through mine pretty frequently. I understand, it can feel gut-wrenching. You are alive now and it doesn't sound like you have symptoms that are attributable to a STI. Indigestion GERD type stuff makes me think of anxiety. Sounds like what happens when I don't sleep (usually because I am anxious about something). Hang in there. Everything is going to be okay. Just hang in there.
If your test results turned out to be negative then trust the system and believe your doctors. I understand your concern but since you've got the results already then stop worrying about it and start thinking about what your condition could possibly be.
Anxiety would have been the best speculation since after the intercourse you became worried already. Consult a psychologist or a psychiatrist. Don't give in to anxiety, it would make you feel like you're sick and weak but maintain your resolve, you can beat it.
Omg.. I've had the same thing happen to me! I started panicking the very next day about "what ifs" and when I got checked everything was negative. This guy gave me an ecstasy pill, told me it was caffeine so I won't fall asleep, and ever since then the paranoia has been real. Although everything came out negative i think like.... I still might have a deadly disease and I'm scared so my anxiety for the past couple of months have been TERRIBLE! I swear I be thinking I have symptoms of stuff and I Google everything then get new symptoms.... It's ridiculous! I think the ecstasy had something to do with it since I already had slight anxiety and a little depression before. Idk I hope you feel better... We're in the same boat.
Im going to retest everything this week at 3 month just ti be sure. I get dry throat specially when im at work dont know if its the anxiety the a/c or the gerd symptoms acting up