Help with Pericarditis

A few weeks back i had a pain on my left side near my heart, i went in to panic mode thought i was dying, went to the hospital they done an ECG they said it was slightly abnormal so they done a blood test it come back normal they sent me home, a few days later after not getting much sleep pain come back just quick half second jabs, so i went back to hospital where i work another ECG it come back normal this time, the doctor said i am so confident it's not your heart i won't take any blood out for testing, the following week i went to my local GP he done an xray it come back that i have a very enlarged heart, but i told doctor i have been jogging up 6 flights of stairs, he said i am confused how some one with enlarged heart can jog up and down stairs so he done a CT scan he was just staring at it, he said hang on maybe your heart is normal size that looks like an enlarged fluid sac next to your heart, so when the xray was done it showed up my heart and fluid sac as one so made my heart look huge on xray i am off to a cardiologist in 2 weeks to see what he thinks.my GP said it was good for me if it's pericarditis not and enlarged heart ,or muscle wall enlarged, i am taking predisalone steroids i do feel a bit better, but the worse thing i have been doing and that;s googling everything because it just put you in panic mode and the anxiety get's so bad can't sleep properly, any help would be appreciated.

I sent you an email thank you very much for your help