Doctors reading, please help?

Ok, so about 3 weeks ago I started to eat healthier than my normal diet, and I also started to do exercise daily for about 2 or 3 hours. In addition I started to lift weights (which now takes up 90% of my exercise time) and I started to eat protein rich foods like lean chicken, protein bars, muscle milk, and lean jerky. I've noticed that my heart has been hurting lately. It's like a sharp pain directly over my heart, but not too intense that it stops my in my tracks. It doesn't occur while I work out, but more like when I flex my stomach or hold in a laugh. I was wondering what this pain is. What's causing this pain? Is it my new protein rich diet? I haven't gone to a doctor for this, and there is no genetic disability in my family that's ociated with the cardiovascular system. I guess I should also mention that I was heavily into energy drinks and suppliments for about a year and a half, but I haven't drinken any since I started to work out and changed my diet.