Every Time I Get Serve Neck Pain My Blood Pressure

Every time I get serve neck pain my blood pressure drops. last Sunday at supper for about 9 people, I started feeling weak, dizzy and my blood pressure dropped to 73/39 - I was taken to the hospital and given was told i was dehydrated and had low magnesium. After and IV I was released. Now the same thing is going on. Every time I get this serve neck pain the low pressure goes down. I have a history of heart trouble and I am on Isosobide, metoporol, simvistain, flomax, plavix, losinoprol, nitrofurintoni, as well as, 4 fish oil tablets a day, vitamin b-12, centrium Silver for mex, and a baby aspirin, I also have a ruptured disk in my back at L-1