Omg Doch...I just read this. This is awful.
I think you did good fragging and tossing the RTN. Instant Ocean is probably the only salt your wife is going to be able to find for you. It is low in magnesium (around 1150 ppm in all my buckets) so you could get Mg down with it. Just make sure you add calcium to it before you use it because calcium is low (~380 ppm). Albeit, IO has high alkalinity at 11 dKH. If it was me, at this point I would be unplugging the dosers and doing daily 10 gallon waterchanges (if using IO bump calcium to 440 ppm to match 11 dKH). I would also quickly get calcium where it needs to be in the display (by testing and dosing several times today if need be...just wait at least 1 hour between dosing and testing). When calcium goes up alkalinity will go down. Waterchanges will bring magnesium down. By tonight you should have calcium at 440 ppm in the display, this will probably drop alkalinity to 10-11 dKH.
On the brighter side, I wonder if the person who sold you the frags would be nice enough to give replace the ones you lost as I'm assuming this is from the recent thread where the OP wanted the corals with someone else as back up for his future tank.