Ok so you're snorting adderall, so its definately not pure. Sorry I was half asleep when I responded before. If you care about your nose I suggest either purify your pills of binders/fillers (search engine anhydrous acetone wash) or get a saline nasal spray from a drug store. That is if your dead set on snorting. A lot of people (me included) seem to find mixing it with warm water and drinking it with some type of antacid ingested beforehand (to decrease excretion of amp) is a much smoother and rewarding experience. Snorting will increase tolerance more rapidly and have much harsher crashes.
All that aside, if you do snort it, the two above suggestions may save your nose. You can even mix the crushed adderall (please tell me ur not snorting xr beads lol) into a nasal spray with water and get the snorting effect with that.
In terms of a benzo for comedown, if you're not tweaking every night, having a low dose of a mild benzo for crashes/psychosis/anxiety problems may be one of the most useful tools you can have, but I would advise you make a habit of doing benzos as well, moreso an only when necessary type of thing. If you want something thatll just knock you the fuck out so you can sleep go for an antipsychotic (lower abuse potential) like seroquel. Z-benzos maybe for sleep too? Ambien?
Ok ill make this more organized tho I am typing this via my crackberry
Magnesium - about 250mg/day perhaps. Reduces tolerance buildup, hypertension, jaw clenching
Benzos - depending on whether anxiolytic or hypnotic etc, they can help you remain functional and alleviate a lot of the psychosis/anxiety as well as help sleep (use sparingly and read or ask about them if you choose any). If taken in low doses during binge perhaps they can help reduce oxidative stress/neurotoxicity (so can not using too much

)
Z-benzos - sleep aids. Ambien, lunesta. For sleep...lol
Antipsychotics - seroquel is all I can think of since its a DA antagonist, but I guess maybe thorazine etc work? They'll probably knock you out
phenylalanine/l-tyrosine - dopamine and norepinepherine precursors, take after binge to help restore you're neurotransmitters
Melatonin - metabolite of 5ht that regulates sleep cycle, easily available otc, not very sedating but may help restore sleep patterns if disturbed
Vasodilators - depending on if its a problem, if you have freezing extremities, ginseng or vincopetine may help dilate blood vessels
Chewing gum - if you grind your teeth
Otc others - valerian root, kava (altho it has mao-b effect so that's questionable), multivitamins or if you're at a vitamin shop look for one of the memory or mind multivitamins with monoamine precursors, gaba, all the stuff to help your brain out. If you're serious about your health and plan on continuously tweaking out send me a pm and ill link you to some bulk nutrition suppliers that will have stuff that will be useful for you in maintaining you're health and be less expensive than the vitamin shoppe etc.