
16M/65kg/175cm

For the past 3 months i've developed a scary cardiophobia, which is affecting my life. 

I've been to the doctor multiple times and got 3 ekgs and my thyorid tested. 
NOTHING.. every thing was normal, but I dont understand how it's normal to get extreme pulse and dizziness with moderate exercise. 

Something like taking the stairs can make my heart pound around 150-190 bpm and then i get this feeling of im going to faint for 5 seconds. Not breathless. This also happens when I stand up after lying, but not as severe.

I've searched the whole internet empty and everytime i become even more confused or anxous. 

Some people say i have a serious heart condition and other tell me its just the anxiety affecting the nervous system. 

I've asked for a cardiologist, but the doctors says im fine. So I just need some reassurence about if it just could be my extreme anxiety affecting my body?

Other symptoms i deal with is pac's and pvc's (less than a thousand a day). The pac's become freaquent after i exercise. I also have these chest pains right where the heart is (Sharp and lasting half a second. Dosent worsen with exercise). 

My resting heart rate is 60

I've also read about pots, but my heart rate slows after standing for 15 second or so. 

Is this really just the health anxiety i have in my head 24/7?