I saw this comment before I replied above.
Welcome to the forum. I scanned your several discussions on the STD community forum and agree with the advice you had there.
The skin changes probably are unrelated to the discomfort on urination. No STD causes "dry and flaky" skin or a "red and irritated" appearance to the penis that comes and goes with sexual arounsal or stimulation; such quick and intermittent color change has to be related to prominence of blood flow, which might be enhanced if there is an underlying skin condition like eczema -- which also fits with skin scaling and flakiness. Almost any skin rash that can occur anywhere on the body can involve the genitals, including eczema. Whether or not it's eczema, I agree it is possible that the same disorder causing the rash behind your knees also involves the penis. Scabies might be another possibility.
As for the burning on urination, you have been treated for all the potential STD causes, i.e. for gonorrhea and possible nongonococcal urethritis (NGU). In the event of persistent symptoms after azithromycin (the single dose of 4 pills you were given), the recommended management is to try doxycycline -- so while I agree it was inappropriate for your doctor to treat you initially without diagnostic tests, both the initial treatment and the follow-up doxycycline were appropriate. Mild symptoms often fade gradually over a few weeks after successful treatment, and it sounds like this symptoms improving slowly. If you observe abnormal discharge from the penis (pus, mucus), of course see a health professional. But I doubt it will happen and your remaining discomfort will fade away. As for the "bump" near your penis, it sounds like you had a completely unrelated minor skin infection -- folliculitis, maybe a boil, etc -- and it got better, either on its own or as the result of the antibiotic treatment.
Bottom line: See your personal doctor or perhaps a dermatologist about the rash, both of your legs and possibly penis; and sit tight on any minor remaining urinary discomfort, which should continue to clear up.
Regards-- HHH, MD
Don't know if it matters but I had a lump just above and slightly to the left of my penis( Some kind of swollen gland I assume) That did start to go down with first batch of antibiotics. By the sun. visit when he gave me doxy script the lump was just about gone.
Sorry didn't know if that mattered.