Yesterday as I was doing my first exercise, which is heavy sets of 2 with a 5 sec pause at the bottom front squats, something happened. The first set was ok. But as I reached the hole in the second, I immediately felt I wouldn’t lift it. My vision started blurrying and my head slightly turning. I couldn’t see anything and the way up felt like an eternity. Once standing it took me at least 5 seconds to rack the bar, my legs were shaking like crazy, a burning sensation was all over my head and I felt all energy had vanished. After I felt pins and needles in my whole body. These sensations quickly disappeared. I took some minutes, dropped the weight by 15% and retried, but the same thing happened, just a bit less violent. So I dropped the workout and just did a bit of easy isolation.
What happened? How can I prevent that? It’s the first time anything like that ever happened in 5 years of lifting