Sometimes i feel like a nut, sometimes i don't.

I find this very odd: I'll wake in the morning with a raging hard one. I'll take the day off from work and go over to the house of one of the three women I'm seeing and we'll fuck and suck each other for two or three hours. I'll go home, take a nap, and then start the same fuck routine all over again. This will go on for a couple of days until I run dry. Then I don't get a hard one for at least two or three weeks! Unless I watch porn or something. I do that if I'm expecting female company to drop by and I don't want to be embarrassed by not being able to perform my manly duties. So is it normal for a healthy twenty something male to be a raging fuck stud one moment, and a shriveled up pansy limp dick the next? It seems that I take too long to reload my lethal weapon. Know what I'm saying? Anybody relate?