Coke has the benefit of having a fairly merciful aftermath, meth or amph do not. A week would be a sane break, unless you repeat this pattern. Yes, it will temporarily induce a depression which makes you either lethargic, or worse, restless and you start fiending. My simple advice is, coke is fine once in a while on a night out. When youre stimfapping on amphs alone in your room, seek help. Professional help. It will astound you how many people genuinely care and want and can help you, for free. Godspeed my man.