I've been battling this problem since September of last year. It has now got to the point where I am usually pain free for a few hours, then I get the discomfort for an hour or two and then pain free again. It's like that all day. My best time is usually in the morning. It is at its worst after I have been sitting a long time - the pressure on them from sitting seems to aggrevate it.

Usually within 12 hours of having an ejaculation, I get a sharp pinching pain in the epididymis. That is then replaced with about three days of achiness (sometimes on the right, sometimes on the left, sometimes both sides). That is why I am still trying to avoid sex until I am all better.