3days ago dr prescribed me im 1g claforan (cefotaxime) and a single dose 1g zithromax curing urethraitis and std, why it is still burning?! but discharge got less.

Improving as expecte: You have been treated appropriately for both gonorrhea and chlamydia, as well as for nongonococcal urethritis (NGU, often called nonspecific urethritis or NSU in the UK). It often takes 7-10 days for symptoms to clear entirely, so it sounds like you're on track. Continue to avoid sex and recheck with the GUM clinic (or whoever treated you) if symptoms are still present after a week or so.