Chest, back, and neck pain

I am a 26 year old male. A couple of years ago i started having palpitations. The doctor told me that I had high cholesterol. I took lipitor for 3 months and then started taking fish oil and garlic oil twice daily. I completely changed my diet and dropped my cholesterol from 254 to 184 which the doctor says is a good number. For the past few months I have been getting pain in my chest, neck, and back. It feels muscular, and it changes from side to side. It also intensifies with stress. The doctor prescribed paroxetine for anxiety, but it doesn't seem to be helping. I am always tired now. I actually fall asleep sitting in my chair at night now, something I couldn't do if I had to a month or two ago because normally I can only sleep on my stomach. I know that alot of the symptoms match the same symptoms of heart disease, but I never feel sick to my stomach or dizzy, and the pain doesn't get worse with physical activity, in fact it gets better. Anyone with similar symptoms with any insight would be greatly appreciated. I'm tired of worrying(I've always had problems with stress and anxiety).