new to this!

Hi im a little scared at the moment, iv just had a thallium stress test and the result was i have a blockage in an artery at the back of the heart. Im on nitrate slow release once a day and i have nitrate spray, my GP said they cant get to it for a stent! so my question is what will happen i go to see the cardiologist in a couple of weeks time, im also allergic the iodine this is also a big problem im told. I have a lot of chest pain and the Dr said its angina im worried im 51 and have just got over bladder cancer ..........well any help will be very much appriciated im in Sussex UK kind Regards Bob