Stuck in an anxiety/ panic attack for days

One of my close friends had recently died of a heart attack, a couple night after i was eating spicy food and had a panic attack due to the heart burn making me believe it was a heart attack. I had nothing after that and was completely fine. Since about 3 days ago i have been feeling very dizzy and having heart palpitations (which have stopped in the last day). One of the days my heart reached 150 bpm and i was driven to the ER where i had an ecg, which showed nothing of concern and the nurse dismissed it as a panic attack. Are there any ways to stop feeling this dizziness and calm my heart down. Thank you :)