You know you shouldn't take it at bedtime right? It's meant for the morning, like coffee for normal people.
OK, so that's what you do probably. As a meth user, that's weird to me, because I think of amphs as shorter duration, and a Vyvanse early in the shift seems like it would be just right. I assume you've played around with timing and taking less?
Or is it too short, you dose in the morning, need another later? THere's all kinds of extended release and instant release boosters and who knows what all the fidgety kids get now.
If you work 12's, is it like three on four off? If you were on a barge doing this seasonal you'd probably not be on the internet, so consider meth! instead (no don't). Then you could cover the entire three days, no sleep no problem lose weight while you work.
Sometimes those long shifts, even without any stims, leave you kind of wired at night. But its a feedback, because you take stims because you're sleep deprived. You might have to just suffer through a whole day without, sleep like a baby, then discover you don't need any the next day.
Just don't start the energy drinks. Meth is healthier.