You are correct to be worried about resistant gonorrhea in Thailand. Throughout Asia many (most?) gonorrhea bacteria are entirely resistant to the fluoroquinolone antibiotics (cipro and others) and many are resistant to the tetracyclines (doxycycline).
I doubt your diabetes is playing a role here, especially if it is reasonably well controlled; and your prior testicular injury is unlikely to make you more susceptible to epididymitis.
Nevertheless, you need to be reexamined promptly. Depending on the certainty and severity of your penicillin allergy, you likely can be safely treated with whichever cephalosporins are handy in Thailand (e.g., cefixime or cefpodoxime orally, or ceftriaxone by injection). Although there is a small chance of cross-reactivity in penicillin-allergic persons, it is rare.
Good luck-- HHH, MD
Thank you very much for your help. I will give those a try, and pass your wisdom on to the doc here in Thailand. Have a good day