I tested negative for stds at 34 days. took zithro (1g) and suprax 4 days post protected sex. burning in tip of penis and after peeing is persistent at 6 weeks out. i have prescriptions for azithromycin, doxycycline, and flagyl. what should i take?

Probably not an STD: If a provider knowledgeable about STDs prescribed those meds, you probably should take as directed; or maybe skip azithro, since you've already tried it. The main symptom of urethral STDs is discharge; pain alone could be STD but usually not. Find STD or infectious diseases expert if your doc isn't one. Exam for discharge when no urination for 6+ hr. Test for UTI and trichomonas (DNA test only).