I am sorry to hear of your experience. Doctor's do not understand that every person is unique and an individual with its own chemistry and equilibrium and when that is disturbed, things go wrong.
My friend is still suffering. She has headache, sweating, formiculation all over her body, even bruising and pain in her legs, but the hospital rejects responsibilities and have referred her to the manufacturer of the drug and reported it to an agency who investigate side effects to medication, but as all of them are now on holidays, nobody is offering much help. I have read that contrast agents are big business, it is the same stuff they use to manufacture CD and palsma TV and in hosptials it is used in MRI scans. It costs quite a bit of money. Isn't this wasting the nation's money with something which can be totally avoided? Aren't there any other natural alternative?
With all the rubbish going on in the NHS, you are scared to enter even your doctor's surgery.