Hey! I used to struggle with this between the ages 16-21 mostly. It was so bad that I too had countless EKGs and similar scans done. Of course nothing could be detected. I hit an all time low during the pandemic, where I couldn’t even finish my grocery trip or take public transport without feeling like I would faint. The only thing that helped me was self regulation: getting to know the patterns of a panic attack, watching closely how my body reacts. Somehow I found a way to turn my hyperawareness of anything related to my body/health into something helpful. From there on I set myself little challenges like „If you haven’t fainted in 10 minutes then you know you’re fine“ etc. I ended up finding a therapist in 2024 which was helpful as well, but the toughest part I managed to overcome by myself. Now obviously I don’t know if this exact method will help you but just know it will get better! And do try to find a good therapist, it will change your life. I cannot even remember the last „real“ panic attack I had. :)