It sounds like anxiety to me but if you are physically worried, I'd make a doctor's appointment (not do the emergency room route) and get a physical and tell the doctor your problems, have the doctor do various tests, etc. to make sure your body is fine and not an issue. I have anxiety and asthma and I can tell the difference. You kind of have to rule out physical problems though, so you can address the anxiety ones.

Too, your other behavior (eating habits, sleeping, interacting with others) can influence and worsen/make better difficulties like you describe.

I suspect that while you were playing the video game, your brain was just in neutral and you had a thought that panicked you; I do that all the time when I'm reading. I can't tell you how many times I am suddenly in front of the refrigerator when I was reading a moment before (my thoughts about what I read making me anxious so I jump up and change the venue, like you can "change" from a book/reading, LOL).

My T use to tell me I was afraid of being afraid and I found that a little helpful. We learn these behaviors and we can learn better ones.