What's going on inside of my body?

Every so often I get incredibly painful chest pains. Not at any specific times. One morning I woke up with horrible chest pains, and every time I moved, I felt an intense shock. Even once when I was working out on the treadmill, I had to stop because it hurt so bad. I don't think this is normal because I'm only 18. I quit smoking a few months ago after my mom was diagnosed with asthmatic bronchitis, and I with acute bronchitis, even though I personally think it was more then that. every time I inhaled cigarette smoke, I became extremely ill and coughed nonstop for days. I STILL even have coughing fits every now and then and I can't understand why. I'm wondering if the chest pains are related to my past smoking. I once went one or two days without eating, and my chest felt very caved in as if someone were squeezing me to death, and I could barely breathe. There have been a lot of times where I've felt like my body wasn't getting enough oxygen. My family has a history of strokes. I couldn't come up with any possibility but angina, anemia, or if something in my body has a blockage. Please help!