Hi Codeguy,
What you describe sounds a lot like POIS to me. Fatigue, and being unable to go on with usual daily tasks, is very common in POIS.
No 2 members have the exact, same symptoms, but the overall presentation is the same: ejaculation-apparition of symptoms- peak of symptoms-slow disappearance of symptoms over days, and this acute phase cycle is usually around the same for a given POIS sufferer, but vary from 1 day to weeks, from one POISer to the other.