I think the problem with sleeping after amphetamine is due to the pathyways down the brain and out the drain.
DA to NE, all the way to cortisol, the stress hormone.
There's many more posts here that are much more in depth. I don't really see another way around it though rather than pure exhaustion; but are the highs worth the lows?
Vitamin C will make will make a person piss more, but it's not really good after d-amps have taken their hold.
Melatonin; I've yet to try. In my basic theory, tryptophan ( from supplements or foods, the likes of turkey) converts to Serotonin; and when it gets dark converts to Melatonin.
From what I read way back, d-amps increase blood pressure; so it's always good to have a beta-blocker at hand, propranolol perhaps.
In the end; you tough it out or take something with a 'pam' at the end.
One drug leads to another drug.