How do i naturally slow a rapid heartbeat?

I am a 40-year-old, 159 pound, white female. I only smoked when I was a teenager occasionally and as a an adult, I would only smoke when I drank (which now I do not smoke at all). I drink occasionally on the weekends but not much. My father had a history of heart disease, emphysema and diabetes. He had his first heart attack in his mid-30s and had a triple bypass in 1983. At age 72, he passed away due to a massive heart attack he suffered as a result of the stress of having surgery to remove colon cancer. Over the past year or so I have been experiencing chest pains almost every day either at rest or after some activity. Sometimes when I am leaning over, I can get the pain in the center of my chest which can feel almost like muscle pain. Sometimes I experience the chest pains with a feeling of shortness of breath yet when I take a deep inhalation, it seems as though my breathing can be restored to normal. Sometimes with the chest pains I also experience some upper back pain across my shoulders. My neck, jaw and arms never really hurt or go numb. Oftentimes, I can feel my heart racing or feeling as though it is going to pound out of my chest. I have had numerous EKGs done all of which have come back normal. I went to the ER in February of 2009 and was admitted due to chest pains. Upon arrival at the ER, I had bloodwork done including my cardiac enzymes tested (which were all normal), an EKG done which was normal, BP (usually maintains at 112/80), pulse and heart rate were all normal. They kept me overnight so I could have a stress done. I completed that the next morning. The stress test I had was where they took pictures of my blood flow while at rest, then they shot me with some dye, then I ran on the treadmill and then more pictures were taken after that. The results were that I had a heart of a 28 year old, and I was in the top 90% of women my age. Then that afternoon, I had an endoscopy done to rule/out any gastro problems. That, too, was normal. I was seen by a cardiologist while an inpatient and he told me that everything was normal and it is very unusual of a woman my age, even with a family history, to have heart problems. It definitely was not a heart attack nor did he feel it was heart-related. Then I had an abdominal ultrasound completed outpatient which was normal as well as which was normal. I also wore a heart monitor for 30 days which allowed me to record all of my episodes. Upon review of that monitor, they told me I had sinus arrhythmia and tachycardia but there was nothing for me to do about it because it was nothing to worry about. My cholesterol is 195 and I can t remember my exact LDL or HDL but I believe the good cholesterol level was 5 points lower than it should be and the bad was good. My triglycerides were over 300 but at my last blood check they came down to a bit below 200. I am still working on lowering those. I know I do not always eat right nor do I exercise very often. I have cut back on fatty, greasy foods and am losing weight little by little. I continue to have these pains either at rest or after exerting myself. Sometimes I take Prilosec and the pain goes away. I mentally make the pain and heart pounding worse because I start to think there is something wrong with me that my PCP and the tests missed. (My PCP is my cousin who is very familiar with my family history and I truly believe he is doing everything possible to find an answer. Yet he keeps telling me that he is 99.9% sure it is NOT my heart. The only other thing he could do is a catheterization. He doesn t want to do it because there is a 1% risk that something could actually go wrong and cause me a real problem. He did say if I had the catheterization, it would completely give me a 100% answer. I actually gave myself such bad anxiety this past weekend that I actually started believing that I am dying or will die soon. These episodes and symptoms are driving me crazy! I want to hope that it is all just stress or something else. I ve been crazily reading things where they say sometimes people can sense doom or feel anxiety right before something bad like a heart attack or death happens. Please! Any help or answer you could give me to lead me in the right direction to solving my problem would be GREATLY appreciated. Janel M.