Neurological injury/damage?

(I am a fifteen year old male, I weigh 140 pounds and I am 5'9)

So, ive been experiencing something for a while. Im not sure, though I dont think it's normal at all. Ive been having this thing happen sometimes when I stretch or whenever I put pressure on my brain (making my face red) ive done it once when I was younger and I heard a pop and then I went unconscious for a moment. It happens alot, and sometimes when it happens I shake in a repeated pattern, I see shapes, nothing feels real, and my body is numbing. And then it slowly fades out. My eyes have been hurting so badly but the eye doctor said nothing is wrong with them, and that it could potentially be something neurological-related. We might go to a doctor to do a scan of my brain or something, but im not sure. Please let me know if this is something that should be looked at immediately, or its something normal. Ive tried doing research, but ive found little to nothing.