Since I had an appendix scare last November, I suffer with health anxiety (hypochondriac). And since December when I started on antidepressants (Mirtazepine). I started having breathing worries and since towards the end of March this year. I started feeling my heartbeat more when I lie down or sit down. So I told my doctor about it and he told me to stop taking my antidepressants, just to see if the tablet had anything to do with it. But I went to the doctors yesterday and he checked my heart and my oxygen levels and it was normal. But I am not convinced. What do I do?