google 'adrenal fatigue'. ill let the doctor explain it more scientifically, but if i remember correctly, basically your adrenal glands can get fatigued when stressed too hard and for too long (could be emotional/everyday stress, or stress from stimulants like those in jacked, amongst other things). this can cause that sluggish 'crashed' feeling and when we just keep putting more and more into our bodies, our adrenals never really have time to rest and just become more and more fatigued. i THINK that this fatigue acts kind of like a 'tolerance' to things like caffeine and stimulants, and we need more and more to get that desired feeling.
problem is, it can take a while for them to 'reset' after putting them through so much stress (i remember researching it fairly extensively after noticing symptoms during exams and while taking max doses of PWO's last year, but have forgotten many of the details, haha).
long story short, DONT start taking craze or anything more 'potent' if you want your adrenals to rest and start functioning properly again. best thing to do is cut out pre-workouts AND ALL stimulants (aside from an occasional soda or something, just no preworkouts, caffeine pills, etc) for a while. i cant say exactly how long, but i went about 6 weeks or more, and once i went back to taking pre-workouts, i was using only a fraction of what i used before. it was hard, and at first i wondered how i was ever able to workout without that 'boost', but after a week or two i started coming around and having more natural energy in the gym. now i only use PWO's a couple times a week or when i'm especially tired, just give it some time.
re: jacked, im pretty sure its the 1,3 dimethylamylamine (sp??) that gives you that 'crash'. i got the same thing when on it, even after not taking PWO's for a while (figure it wasnt my adrenals), as well as when i took 1mr and others containing 1,3. honestly, i have absolutely no scientific or medical basis for saying this, but personally, i like to stay away from the stuff, but thats a whole different story for a whole different convo.
