Again I have only read the first post so apologies if this is a repeat but: Take in plenty of complex carbs before and during the exercise, and a recovery drink as soon as you get back followed as quickly as possible by a carb and protein rich main meal. Sounds to me like you are well hydrated but no more.
If riding for over an hour I tend to use energy drink (exactly that – a compex carb based energy drink not just a rehydration drink) at a varying concentration depending on how much I have eaten – so less for evening rides after dinner, more for weekend morning rides. Then, if it was a hard one, a recovery drink as soon as I return.
I only ride twice a week so could survive without this, but it makes a big difference to how I feel the next day. Without it I’m a moody git, with it I feel fine.