I want to add, I'd be very interested what nursegirl has to say about this.
Such a short course of Ativan shouldn't cause withdrawal, but "should" is a word with no meaning when it comes to real life -- things do what they do. I always say that if something new follows stopping a med and nothing dramatic happened in between then you're probably having a reaction to the medication. Doesn't mean it's absolutely true, but it's the only logical thing. Benzos are also anti-seizure meds, and so stopping abruptly can cause seizures, but usually not when you've only taken them on such a short term basis. Still, you're suffering what you're suffering and no medical reason other than the abrupt stopping of the med has been found and you've looked pretty hard. That being said, it's hard to know what to do. What form of magnesium did you take? Some forms are not well absorbed, some are better absorbed. Did you take it with meals, when minerals are best absorbed? Now, I'm not a doctor, and I can't tell you what to do, I can only suggest something that might help. And I can only think of two things. One is to go back on the Ativan and see if your symptoms go away, which would indicated that's the problem. Then you'd have to very slowly taper down off of it since you have this unusual sensitivity to it. You could also try to affect GABA in another way, as this is the neurotransmitter targeted by the Ativan and other benzos, and that would be to take some taurine, a psuedo amino acid plus some B6 for a few days. These are the two main factors the body uses to manufacture GABA in the body, and it might be enough to let the body re-regulate your GABA system. They're not nearly as strong as a benzo, and if you get worse, quitting them is easy. It's just a shot in the dark if you don't have any other answers. You might try discussing this with your doctor first if you have one who understands how the body works without medication and is open to alternative approaches, but don't be surprised to be pooh-poohed that the quitting of the Ativan could be even remotely responsible -- that's how docs are trained. Again, this is just a suggestion, because I have no idea if the Ativan is truly responsible or not, but again, you've ruled out the alternatives.