Thank you for posting your query at DoctorSpring.com
I have gone through your query and i personally feel you need repeat your test for syphilis. These lesions appear to be lesions of syphilis and you need to be investigated again.
The other possibility as was diagnosed by your local urologist is NGU ( Non-Gonococcal Urethritis ). Since mostly the bacteria causing this problem is difficult to identify it is difficult to treat also. Sometimes they take close to 3-4 weeks to disappear and hence medicines need to be continued for that long.
I will advise the following :
1) Abstain from having sex or getting oral sex from anyone with unknown STI status. It will further endanger your life.
2) Don't have sex for the next 4 weeks. Give it enough time to recover. In such cases, if you receive oral sex even normal mouth flora can lead to further infections.
3) I will advise Tab. Cefixime 200 mg twice daily for 2 weeks. If the lesions still persist it needs to be taken one more week. Please abstain from any kind of sexual activity in this period.
Also once again you need to repeat the test for syphilis to rule it out completely. Since you have pustules at present this will be the best time.
Doing oral sex is as dangerous as intercourse and you could have got infection from oral sex.
Hope this was helpful,