Ive written about this before but Ive done partial hanging while incredibly drunk. The alcohol and grief overpowered my SI easily. I hung myself and lost consciousness.
Of course, somehow I managed to regain consciousness. I had to claw really fast to get the noose off me before I went unconscious again. I could see the darkness coming on.
When I regained consciousness I was still drunk and confused and my body just kicked into survival mode.
I personally dont remember experiencing much of a head pounding for too long- i was passed out really fast.