I think I have this same symptom you speak of after starting NB Balancing + a digestive enzyme containing bile salts amongst other things. I think the digestive enzyme made me release old bile (?) or something like that and screwed with my gallbladder and/or liver. When you feel like your heart isn't working properly or you feel like you could faint, is it like an extremely lightheadeded feeling? Like your brain isn't getting oxygen? The feeling I get now is hard to explain, but it's very scary. I hope we both find out what's wrong + a solution. Let me know.