Throbbing Headaches in Chess.

I love playing chess and studying the game. And I always try to find ways in improving my game. However I notice that when I engage in really hard chess exercises or find myself struggling to find out a puzzle, my temples start throbbing and I start to feel pressure. As if someone is like squeezing the sides of my head. However, the pain felt really intense when I was doing a chess exercise called "Guess the Move" where I take about an hour or so anticipating moves of gms and scoring my own moves. After that, my i felt a lot of pain and laid down on my bed for a good 15 minutes till the pain went away. I start to wonder if I'm even capable of playing tournaments in the future because I worry that I'll start feeling this pain again.

That's happened to me before. I just splash cold water on my face, it seems to help haha

haha i'll just soak a towel and put it on my face then

In any case, with practice your brain will get used to exertion for long periods, so it's all good.