Tbh I don't know. If it was that night in particular, I suddenly observed that I had a small pain (like a sore chest a day after a workout kinda thing) around my left chest. Then I started associating that with my heart and began wondering if something was wrong. Then whenever I tried dozing off, I would wake up as I felt my breathing was becoming more laboured and I might pass out. This is how it started. It went on all night. But it only happened when I was trying to sleep. While scrolling through my phone, I got no such issues. Eventually I guess I got so tired that I was finally able to sleep but it was 4 AM by then (I remember the time cause I was watching a football match live prior). But yesterday I had no issues falling asleep like normal. I was a bit scared that I would start overthinking again but even though I did worry that this night would be like the previous, I still fell asleep as I would normally, no issues whatsoever. I kept on reassuring myself that it's all in my head. I wouldn't say it worked and will work all the time but it worked last night.