What Are The Early Signs And Symptoms Of Heart Attack?

Hi, my name is vickie I am a 45 year old female. I had symptoms of heart attack from 2000-2008 I had been seen several times at doctors office & emergency room during tis time. My symptoms were severe head pain like no headaches blurred vision at times I couldnt see anything, I couldnt walk but a few steps, unconsciouness, weak,left arm pain, lower jaw pain, chest pain,upper back pain, swelling in legs, legs painful to bend,shortness of breath, memory loss, several other symptoms. I thought I would die before any doctor would find out what was wrong with me. Finally in 2008 I found new doctor who listened to my complaints, listened to my breathing done EKG and said he was sending me to cardiologist for stress test, I saw this cardiologist for the first time when I was 43 years old for my tread mill test I told the cardiologist & his staff I didnt think I could do this test they ask my age I said 43 they said awww you will be fine we are gonna be right here with you well I walked 1.5 minutes and had heart attack then I was admitted to hospital then sent to another hospital next morning for stent surgery. I had what they called a widow heart attack it was my left side of my heart. Now I went to see my cardiologist just last week and I told him I had severe chest left arm and jaw pain in Jan. and I had to take 3 nitros he said he didnt think it was my heart causing the pain I said to him it was the same pain that I have had for years before my diagnosed heart attack he still didnt think it was my heart I ask him for another prescription of nitro medicine because my bottle is getting to be about 5 months old and I have been told replace it after 6 months well he wouldnt give me anymore nitro medicine he said it was dangerous for me to take. I dont understand what is going on I know what kind of pain I have its the same as before my MI why wont my doctor listen to me? do you think I need to find another cardiologist? I am really afraid of having this chest pain and not having the nitro to stop the pain it scares me. I have on my medical records CAD, LAD, does these diseases usually cause someone to need nitro? please answer my questions I dont know what to do. Thank You So Much!!! Vickie