This sounds totally normal to me, as someone who took ~40mg prescribed dexamphetamine daily for most of 2 years a few years back.
There is a genetic element, for sure. I have a friend who can just somehow make himself sleep a short time even after smoking meth, always. For me, the sleep disruption sets in almost immediately, I think it does for everyone, frankly, albeit more subtly for some than others, in that if you're stimulant naive you generally just won't notice the effects of the severely degraded quality of sleep you're getting even if you think you're sleeping a full 8 hours or whatever it is you need - and of course, there's significant genetic variance in how much sleep humans need anyway. Either way this accumulates until you're always running on a cognitive deficit which you try to prop up artificially with your drugs (prescribed or otherwise) but of course the human brain doesn't really work like that and currently no stimulant is an adequate replacement for a proper, regular sleep cycle.
The same applies to everything else. You have more energy, you're thinking faster, but that comes at a cost of jacking up your metabolism and burning calories faster to fuel that feeling of energy, so it really isn't enough to just make sure to eat what you normally eat, you really gotta eat more than you'd normally eat to make up the deficit, and even then of course the human body just doesn't work that way in that it's a perfect calories to work converter, the artificial and temporary metabolic boost is straining a bunch of biological systems, and disproportionately, so just eating more even if you really do manage to make up for the excess energy burn isn't actually gonna be enough to avoid gradually knocking a bunch of homeostatic mechanisms off-kilter until you just start to feel more and more easily drained and unwell, the constant spikes and crashes from dosing do a number on a bunch of bioregulatory systems, ALL of which have knock on effects on your brain which is now wasting additional energy trying to compensate for all the chaos going on in your body and autonomic nervous processes. Genetics as always plays a role, some people just tolerate this kinda disruption better, but ALWAYS it eventually starts to degrade functioning beyond the point that just taking more drugs can fix it so that even your supposedly "enhanced" peak functioning at peak blood-substance-concentration or whatever is now under your pre-stimulant-adapted baseline. Honestly this maladaptation I think always starts from pretty much the very first dose, your body has to do work to recover from the artificially induced asymmetric strain put on all the systems that contribute to the good and desirable feelings. There's genetic variance in how NOTICEABLE the first stages of decline are, the impact of this extra work, but it is ALWAYS happening.
Dexamphetamine despite it's pharmaceutical legitimization is a hard stimulant which is just not sustainable to take in the long term for all but the tiniest minority of genetic freaks who somehow just don't experience the same dysregulation (and I think these people are extremely rare - I mention it just to cover all bases, really). Most people who believe themselves to be fine taking it long term are, IMO, in fact somewhat in denial about their fairly obvious stimulant addiction even if they are in fact more functional in this brutal capitalist dystopia than they would be without it, and many of them will eventually find the negative effects unbearable before they manage to construct their lives in a way that a multi-year post-stimulant withdrawal of useless, soul-crushing apathy is not gonna be a major disruptor to their lives... but of course, all of them within this dark pattern are hoping to JUST MANAGE to make enough money, finish whatever projects, set up their lives in just the right way before the neurobiochemical shit really hits the fan from the effects of taking a hard stimulant almost every day and they can no longer sustain the lifestyle that they feel they need to, for whatever reason, and are taking the stimulant to maintain.
As far as people who love stim benders... I dunno man, I'm doubtful they actually exist. There's people who THINK they love stim benders, for sure, but IMHO they're mostly "chasing the dragon" and in love with the anticipation of a reward that might come once or twice on day 1 depending what kind of bender we're even talking about, and after that it all gets pretty dark pretty quickly. Of course no-one likes to admit the sheer undeniable dysfunctionality and horror of their totally dysfunctional habits outright because it's so hard for any of us to understand why we would do this shit to ourselves, so they delude themselves, rationalize it, I mean don't get me wrong there's situations that can be very very fun for days on end, on stimulants, but those situations (music festivals, multi-day raves, mainly, I'm thinking) are enjoyable not because of the stimulants, but in many cases IN SPITE OF the stimulants... a pure multi-day stimulant binge where the constant redosing of the stim is the main event with no other plan... nah, I just don't believe that's ever fun, actually. Day 1 is fun, day 2 might be OK if you're young enough, stim-naive enough, or one of those genetic freaks, if you're enough of a shamamistic type that you know your drug combos and can augment the darkness and onrush of suffering with some other substance... but this is rare.... day 3 and beyond.... nah, just don't buy it.
) and that was that. By the end I was railing 2 30s for a 15-minute buzz. It was NOT fun recovering from that one after the intensity/consistency of that run. Well over a decade later and I still can't touch the stuff. They possess no recreational value whatsoever to me. No euphoria/hyper sensuality/grandiose thoughts or epiphanies, no 'remodel the house' energy, absolutely nothing. Nothing but feeling like shit. From what I've seen speed is one of those drugs where all positive effects wear off fast, and the magic never returns.
