The only symptom you describe that suggests an STD is the initial urethral pain, which could have been due to urethritis (gonorrhea, chlamydia, NGU). However, with negative STD tests twice and with doxycycline and other antibiotics, you can be assured that's not a problem now. None of your other symptoms suggest STD at all. If youe penile skin really is discolored, see a dermatolgist--but color alone without actual rash probalby isn't even abnormal, maybe just natural changing of pigment with age (??). Most people who perceive their own lymph nodes to be enlarged are wrong--that's a sign than needs to be confirmed by a health professional before I can coment further. Cerrtainly the rectal bleeding/hemorrhoids, changes in semen character or volume, and swallowing symptoms do not suggest anything significant.
All in all, it sounds like the STD clinic is right. If your symptoms persist, see your personal physician, but you can be confident that an STD or HIV is not in the picture. All your symptoms probably are coincidental with your sexual exposure in Las Vegas, except for the possibility that anxiety over the event may be contributing.
Best wishes-- HHH, MD
I have a similar story. 2 weeks after unprotected insertive oral sex with "Pro" I got that fullness in the ears feeling, pain in the urethra and testicles, happened more during ejaculation (protected sex with wife) and urinating. Also noticed that the semin was very inconsistent.(small clear lumps through out it?) Have small blemish on top of shaft that has flaked over several times. Also had pain in the rectal area. I read that sometimes the lymph nodes in that area can swell causing pain. Discomfort in the general groin area. Also swollen lymph nodes in the neck confirmed by MRI. Many other symptoms as well. I tested for several stds and neg. My biggest worry is HIV and have tested Neg. out to 4 months by 4 PCR and several Elisa tests. So it does not appear to be HIV but I am not done testing yet. I will be testing out to 6 months to one year. Because PCR is not to be used for routine screening, although is an accurate early test and the 6 month CDC window period with Elisa testing is why I will continue testing.
I,m just being very very thorough. I really don't think your test results or mine will change. Hopefully our symptoms will!