The first time when I failed and damaged my brain, I was sectioned on a section three in the mental hospital. That's six months long. I made a noose out of bra straps tied together and found a ligature point. I noticed all the staff were busy with an emergency and with my ligature ran to a bathroom (that at the time was awfully designed to ward off hanging risk btw.). I ran into a (what was supposed to be locked) bathroom and hung myself. I was so close, I had what Dani paradox explained. Went deaf, tingling in face, just felt like i was falling into a black hole and i knew it was a matter of time before that was it. Head pulsating etc. Then they were shouting my name running about the place to find me. They did, kicked open the door cut it off and I was taken to hospital. Face was mottled and had blood-rash all over , eyes and face for weeks and a bruise for god knows how long.. hence being so mad I didn't make it, I knew i was just so close. Anyway. that is that. I killed my brain cells.
How I failed a few weeks ago. Crap ligature.
I was experimenting (this is going to sound so stupid, but I was looking to make it more comfortable) I put the noose around the bed frame (solid oak, so quite sturdy) and lowered myself forwards towards the ground face down on my knees (going from kneeling position, to laying on tummy with arms at my side.. As I did so, I passed out very quickly (compressing left artery) and came to, whacking my face. The belt had loosened as I passed out. So whilst there was initially enough pressure to make me pass out, it wasn't constant, the moment it loosened blood rush back to my brain, and boom. Fail. I was kind of desperate though, I was using a thick leather belt. Not a good idea, though i know if i kept trying, and used a proper hanging point, it could have worked. Could. But i'm not going to consider it again
That's not to say hanging is unlikely to work. Its very sucessful i know that. But though i've come close to succeeding with it i'd personally not try it again, only because I find CO peaceful and has around the same success rate.