Very good post but you appear to have missed one issue.

Your current struggles can be caused by the video game marathon over-stimulating your brain. And OCD brain, by definition, is already struggling to manage stimulation. 4 hours was easily over-stimulation.

I would also suggest you find a physical therapist or chiropractor who can gently help you with your neck and back after these falls. The neck tension of 4 hours of video games combined with a stressed neck could easily cause your headaches. If you have soreness or stiffness in the area behind your ears, the headaches would usually be due to spams in these muscles.

For many of us, we know that maintaining our neck and back with proper spine manipulation/therapy can reduce these other problems.

You would benefit from finding the chiropractor or physical therapist who understands how these issues all connect. Very few do.

When my back or neck gets tweaked, the $45 fee to my chiro for 30-45 minutes of back and neck work is well worth it.