Some think magnesium/calcium ratio should be 1:1, and some say 1:2. Either way, its known that both cal and mag need to be taken. So definitely invest in the cal citrate. Twitches are very common with low cal (as well as low iron)
On the iron... I'd suggest you ask the doctors for your specific results/numbers next time. It was only when I inquired about my actual numbers that the doctor told me that I was "borderline" deficient, but not in the clinical boundary to actually report or treat it... and I had numerous symptoms indicating iron deficiency. Had I not asked my doc, I'd never had known I was lowish.
Good luck. I'm sure that if you sort out a few supplements you'll definitely improve.