Heart problems or drug side effect? Thoughts?

[Matiadbueno94]

Im a 23 year old guy, used to be very active and did sports most of my life until a few months ago. I have rdont all bad anxiety about health and sudden death so i saw a cardiologist. He did a few ekg's, echocardiogram a stress test, and 2 echocardiograms which came back all normal. One night on december 27 i had an allergic and went to the ER, where they gave me prednisone. The next night i felt palpitations and my heart racing extremely fast which made me think i was dying so i called 911. They ran a few ekgs and blood tests and nothing was found. They also gave me a 30 day monitor to calm me down that i had to wear around. Whenever i had symptoms i would press a button and record. I constantly felt like i was dying and racing heart but according to the montitor it was always anxiety. 2 weeks past and i was a little calmer, then once again i had an allergic reaction and went to the ER, where they gave me prednisone once again. A day and a half later i had palpitations which my monitor picked up and got a call telling me to go to the ER. Where they said it was an episode of monomorphic ventricular tachycardia that lasted 5 seconds. I was admitted, kept for 3 days where they did a cardiac MRI and an EP study, which were also all negative. Im terrified, how is it possible every single test came back negative and that happened? Could it have been the medicine prednisone? They gave me 60 mg both times and its weird how a day or a day and a half later i get these episodes. Now im taking flecaidine and metropolol without knowing if i really need to. Ever since i started taking them ive gotten one or teo PVCs a day, which never happened to me before. Its extremely hard not knowing, and trying to differentiate between anxiety and panic, drug side effect, and an actual problem. My other cardiologist told me to only take motropolol cause its a safer drug and the flecaidine can cause me to have bad rhytms if i dont actually have a problem now. Any thoughts?

[Matiadbueno94]

2 stress echocardiograms****