Please clear this up -- did the doctors ever actually diagnose you with pvcs? You seem to say no, they didn't. You say you were diagnosed with them but that testing came out negative for that. You also say you had a test for TSH, but that only indicates the possibility of a thyroid problem, it isn't sufficient to confirm it. For that you have to get the individual hormones tested. A lot of anxious people think they have a heart problem going on when they actually don't, they just feel anxious and that makes them feel like their heart isn't functioning properly. Also, childbirth and pregnancy makes your hormones fluctuate radically, which can cause a lot of women to suffer depression (usually called post-partum) and anxiety. The problem isn't mental illness in this case or if there's a heart problem or a thyroid problem or some other physiological problem, the problems is whatever is going wrong in your body. Mental illness has no known cause, so if you eliminate everything else and nothing is found, then you've got chronic anxiety and it's time for therapy and perhaps medication or lifestyle changes and all the other things different people have found helpful.