Is this an STI?

My story:

Feb - received unprotected oral

After 10 days - symptoms:
* Frequent urination
* A small red cut-like mark near the opening of the penis
* Swollen head of the penis (swelling on one side, left or right, at a time) - disproportionate
* Rough and raw looking penis head
* Pain in urethra
* Slight pain in testicles
* Slight anal itching
* Occasional joints pain
=> Consulted a general physician, had urine analysis for all bacteria, negative results, no treatment, symptoms disappeared in 4 weeks

Sept - received unprotected oral (not again!)

After 10 days - symptoms:
* Frequent urination
* Red cut-like mark near the opening of the penis
* Swollen head of the penis (swelling on one side, left or right, at a time) - disproportionate
* Rough and raw looking penis head
* Pain in urethra
* Moderate pain in testicles
* Slight anal itching
* Joints and muscle pain
* Groin pain and tender bladder area after 4 weeks
=> Consulted 3 urologists, the first one found prostitis (swollen prostate gland, maybe due to a urinary infection), put me on Cipro 500 for 30 days, no improvements in symptoms, the second urologist recommended a CT scan for kidney stone, came negative, just visited a third one and he is retesting everything. After 5 weeks, the symptoms seem to be improving - prostate gland seems to be better, no testicle pain, bladder is improving, the cut on the head is disappearing

Still not 100% cured, want an answer to this... Is it a recurrent problem? Is it chronic? Is it infectious? Is there a diagnosis & cure for it? Is it fungus, some virus or some restrained bacteria (that is yet not identified as STI)? All my docs think that this is not STI, but I believe it is an STI.