you might have already read this, but i found this page for ya
http://www.ehow.com/about_5530827_side-effects-stopping-phentermine.html
Phentermine is an amphetamine that should only be taken for 6-12 weeks, my mom used it back in the 70's. If taken long enough, it has classic amphetamine withdrawal, mostly fatigue, depression and craving for the drug. How long where you taking it?
This is my 6th month...I talked to my Dr today only because of my lortab addiction and being on day 5 of coming off that and she is going to wean me if it.