When chlamydia causes testicular pain, there is swelling and marked tenderness to touch, not just aching pain. Also, epididymitis would have either gotten much worse or gone away long before now; it doesn't linger for 2 months. Finally, you cannot catch chlamydia by oral sex--or if it happens, it's too rare to worry about. (Chlamydia doesn't infect peoples mouths or throats, so there is no chlamydia to pass on by oral sex.) Gonorrhea is possible, but almost always causes discharge, and does not cause testicular pain without swelling. And in general, oral sex is low risk for most STDs.
Your symptoms really don't suggest any STD, and probably are entirely unrelated to the sexual event you describe. However, they might be due in part to anxiety over that event; anxiety and stress can make otherwise normal body sensations seem painful.
But you should see a health care provider to check it out. A family doctor is fine; or if you don't have one, visit your local health department or a community clinic. In the meantime, don't worry about this. It doesn't sound like anything serious.
Good luck-- HHH, MD
How long it takes before gonnorhea enter into the blood stream, my friend found out that she has gonnorhea after 6 months, cause she didn't have any symptoms except unusual vaginal discharge...can it still be treated?