Urine analysis, chest x-ray, ultrasound are normal, ultrasound showed epididymal cyst. No antibiotics have worked. Could this be tuberculous epididmitis?

TB epididymitis. Epididymal infection due to tuberculosis is very rare, although the epididymis is the second most common site in the genitourinary system to be infected with tb. Unless you know you have had a significant TB exposure, this diagnosis seems unlikely. Benign epididymal cysts, on the other hand, are quite common and nothing to worry about unless they are hurting or enlarging.
Not likely. Epididymal cyst is not due to infection and is not expected to respond to antibiotics. See this site for more info on scrotal lesions. http://www.mayoclinic.com/health/scrotal-masses/ds00410/dsection=causes.