Epididymitis?

Hi Dr. Hardy,
About 30 hours ago I was getting off a plane and noticed some mild pain, more like discomfort in the right testicle. Upon examination, it seems like the epididymis is swollen and tender to the touch. It has improved since then but is still not completely normal. There are no urinary symptoms at all. There is no pain upon urination or ejaculation. I haven't been sexually active for over 2 months so STD seems unlikely. I was playing with yourself, spanking the monkey frequently before this occurred,about three times a day for a few days. I did swim in some lakes where there could be something infectious and I did swallow some water. I was in Tennesee and also got bitten by some horse flies and damn they bite hard. There is a cremaster reflex and pain was never above about a 2. Elevating the testicles with supportive underwear does help. There is no discomfort at all unless there is unsupported movement or touch.
I am going to urgent care tomorrow just to be safe. I assume they will give me antibiotics. Is this wise and waht else can I do if it is epididymitis? I am using colloidal silver and topical antibiotic in the meantime. I have no signs of infection like fever, nausea, loss of appetite etc, I don't feel ill at all. Any thoughts would be appreciated. I have never had anything like this, I am extremely healthy, 41 year old male very into a helathy lifestyle. I have no medical conditons. Thanks.