almost certainly it is a tolerance thing, and also just a time thing... If you've been doing successive crack binges for two years, i can easily see you experiencing increasing wear and tear as the benders continue. downregulation of serotonin, dopamine and norepinephrine receptors is a serious thing and of course it will affect the experience you have.
if you keep mashing a button repeatedly, it gets worn out. doubly so if you are mashing a button that comes with a massive dump of stress hormones etc. --- anyone binging on crack form multiple years is going to get increasingly tired and worn out, with increasingly little positive effect during the binge, it's how it goes. if it was a fentanyl issue, you'd be having overdose or other serious issues, not a lasting feeling of tiredness. That is from running your body too hard. I'd suggest sleep, good nutrition and time off of cocaine to restore some positive effect. It is important to note that even all of that won't do much beyond giving you a few good hits, once you've messed with a receptor system it gets out of whack more quickly when you come back and do more of the same. --- A person who has had a long history with ketamine, or morphine or cocaine and stops for years might have a few good experiences coming back, but they will rapidly revert to the tolerant state.
truly, less is more when it comes to extending the amount of time you can enjoy an exogenous(from outside your body) compound. When i see younger folks now having a great time on booze or coke or something i tell them plainly "if you LIKE this feeling, and want to continue getting it - do it as little as possible,"
