maybe some of the more educated getbiggers can give more of an educated response, but yes, I believe so.
yes you need a good hormonal balance, studies in men with supressed eostrogen have found a correlation between this and their low sex drive despite suplementation with exogeneous testosterone.
Plus, with that extreme dehydration, I would suspect their prostate being dry as a raisin and the cramping is another issue, when you ejaculate your prostate spasms and if you're prone to cramping it could happen to it and its painful.
I know this cos it happened to me, I cramp a lot on winny when im dieting, and once i remember towards the end of a sexual encounter I came, and got a cramp in my prostate and my toes simultaneously as I was ejaculating, the prostate cramp feels like a knot by your anus. So I immidiately stretched my leg and held my toes, once that went I did the splits Van Damme style butt naked in the room whilst the girl was watching and it relieved the cramp in my prostate.