Coping With Chest Pain

for the last couple of years i have had chest pain and shortness of breath, even to walk to my front door causes shortness of breath, the chest pain comes at anytime even when just sitting quietly or walking. i have been to there cardiologist, two of them said,there is nothing wrong with me,they gave me stress echo, echo, and stress thallium, they will not do angiogram as i have severe allery to iodine,so both say there is nothing in the tests they have done to indicate they should take the risk of angiogram with me. i went to the third cardiologist who said he thinks i could have aortic stenosis and said i should have angiogram,this assumption was made with just a basic ECG,no stress echo or no thallium. i am at my wits end as to know what to do.