I dont know enough about the magnesium you use, but as a general rule; it is better without calcium, it is better as an acid (malate or citrate are those that works best for me) and if possible without binders and fillers.
I recommend you go up to 400-600 mg daily for a while. And a good B complex if you dont already.
"Magnesium deficiency causes increased levels of adrenaline, which can lead to a feeling of anxiety. Rats who become magnesium deficient have an increased level of urinary catecholamine excretion (a by-product of adrenaline)." http://www.ctds.info/5_13_magnesium.html