What Causes Burning Sensation And A Bump On The Penis?

I had burning and 1 what looked like a pimple on my penis. I went to the Dr and he said that it was probibly one of the curable STD's because it wasn't an open sore. I took a urine and blood test and am waiting on the results. But now when I try to go knowing its going to hurt I can't it drips almost like going through a filter or if I push really hard it goes hard but HURTS. My Dr put me on ciprofloxacin 500mg twice a day which he said would kill most bacteria and 1 dose of azithromycin 1000mg. When will the pain start to go away? And what STD do I probibly have? The sores don't hurt.