Welcome to our Forum. From your description, I'm not completely sure that you had epididymitis but I'm glad that the therapy you have received is helping. I'll tell you why I'm suspicious that you do not have epididymitis first, then answer your question.
In men, epididymitis can present with scrotal pain. It is typically not intermittent and tends to progress over the course of just a few days. It is most often caused by gonorrhea or chlamydia in men under the age of 40 although it can be caused by the same, non-gonorrhea, non-chlamydial organisms that cause urinary tract infections or prostatitis. It would be most unusual for you not to have white blood cells present in a urine or penile swab specimen if you had epididymitis. Based on this description, I wonder if you might have had something else, perhaps a urinary tract infection, prostatitis or a recently recognized problem described problem called the Chronic Pelvic Pain syndrome (CPPS- well described in Wikipedia).
Now for your questions:
1. Gay men are not more vulnerable to epididymitis than heterosexuals. In both groups it is rather uncommon.
2. Anal penetration with sex toys should not cause epididymitis. Epididymitis is a complication of infection of the penis/urethra.
I hope these comments help. No matter what was going on, it sounds like you’re getting better- glad to hear it. EWH
Thank you for your answer - it was very helpful. The reason I thought it was epididymitis is because my testicles were sore, especially around the back and the epididymis did feel swollen.
It could be epididymitis but I'd worry about the other processes I mentioned. Either way, I'm pleased your getting better. EWH