lol yea man, thats just gonna compound health issues, but even at 20% purity 3 grams, really? was this verified by scale? i mean im not saying its impossible... but damn near!! seriously, it had to of been some bunk, amps should keep you goin in between doses for a while, if its real you shouldn't have to snort it all day ( which you must have LITERALLY been doing, like all of you times a was spent snorting or getting ready to snort), ITS NOT COCAINE, now 3 grams of cocaine in 24 hours is not out of the question but still a large amount.
just be careful because seriously if one day you get ahold of some "real" (meaning higher percentage) amphetamine dont snort it like this do some give it time to work then go from there...