I'm not taking it anymore but I was put on anti-depressants to help me through the withdrawals, it's the serotonin that is responsible for managing your thoughts, mood, and melotonin -> sleep cycle You definitely don't want to get hooked on some sleeping pill! Not sure how long it will take, there is a supplement, L-Tryptophan which is supposed to be more effective it's a little more expensive though, you can find at any vitamin shop, just don't over-do it.
http://www.raysahelian.com/tryptophan.html
http://www.raysahelian.com/tryptophan.html