Perhaps it's just the sensory deprivation that makes one more aware of processes within the body that otherwise go unnoticed among the bustle of regular life?
Possibly but he has been deprived on other occasions when he was using Ilfosol and his symptoms were much less or we talking now not about the OP's issue but about the causes and symptoms of sensory deprivation in general?
I am deprived of light for the time it take me to load the film on the reel and shut the tank lid and I see no reason why the OP's deprivation is likely to be any longer than mine, say, 5 mins max . Is 5 mins in the total darkness going to lead to the symptoms he has mentioned? I hope not, otherwise he may as well give up film processing