What the hell was wrong with my heart rate?

I took a warm shower today, but it was a little too hot. By the time I was finished, my pulse was already racing. My heart was beating faster and faster. On the way to my room, my vision suddenly became extremely blurry and I couldn't see clearly anymore, and then it happened! I just heard a loud crash. I woke up on the floor 15 seconds later. But there was no pain in the back of my head or anything else. Still, it's very questionable. Why did this happen to me?