hey guys, i'm 19 and i've been experiencing anxiety for months now, it first started with heart worries then turned into kidney worries, brain tumor worries then i calmed down for about a week/two or so i thought...recently ( two days ago ) my heart "problems" came back this time its the feeling of my heart wanting to give out when i stand and tbh it only seems to happen when i pay attention to my heart before getting up and recently, short stabbing pains around heart, tightness around heart, rapid heartbeat and heavy breathing when doing heavy lifting or if i start thinking about how i breathe, an example of it: today i was lifting three concrete plant pots weighing about 15-20 pounds each and had to carry them about 40 feet one by one, now i'm a fairly slim guy, after i was done my heart was racing and my breathing was very heavy, felt like i just ran a marathon which got me really worried. sometimes when laying down my heart feels like its racing but when i check it, its beating at the same rate it always does (88bpm). i've been to a cardiologist about 2 1/2 months ago and nothing wrong could be found, he even requested a full panel blood test which came back normal except that i had anemia.i've been taking iron supplements since then but I've only been eating a big meal about once a day for the past two weeks and then only snacking on small things like fruits or granola bars because with anxiety i just lose my appetite. it has started to make me feel really tired all the time even when doing nothing. The tired feeling starts roughly 5 hours after waking up, I'm assuming lack of eating, anxiety and anemia all together could be more than possible to cause this and could even cause the "heart problems"but today I've tried changing that and i've had 3 big meals along with snacks today, dont feel as tired today but still do. i'm trying to tell myself its just the anxiety causing this but my body just doesn't want to listen. its gotten to the point that i hate standing up because the rapid heartbeat feelings and fluttering comes on.