What kind if doses were you taking, and perhaps more importantly, how many times a day were you taking it.
I took well over a gram (closer to 2 g) every night for quite a few months, but only at night, and to my surprise experienced no apparent withdrawal. I think the withdrawal syndrome occurs when you're taking it round the clock for an extended period of time (similar to alcohol, which takes pretty heavy 'round the clock abuse to actually become physically dependent).