Two weeks ago I experienced my first Panic attack lasting 4 hrs. Then yesterday it happened again (it was better, but still awful)

I went to the ER both times. The first time my heart rate went up to 180 and the second time I felt extremely dizzy and a knot in my chest. My arms and legs were also tingly.

The doctors did EKG's, blood tests and X-ray's (heart and lungs) on me, but everything was "fine".

They told me I had a panic attack and that I might have anxiety, but I don't think so. They then told me about panic disorder, but Idk.

I've never had any health related problems, I feel a normal amount of stress in my Life, and I'm not depressed. I'm pretty average for a 20 yo male.

Can any of you guys give me some insights into what could be wrong with me, and what steps I could take. I'm really scared of having another panic attack. It was the worst feeling I've ever experienced. I thought I was dying🥲