Ime its important to make sure the drop is sudden and forceful (ie you don't want to lower yourself into it slowly, you want the full weight of your body being put on the knot/noose at the same time.) I was worried too about how long it would take to lose consciousness because the videos of people struggling for minutes are horrible. But with a forceful drop, the noose tightened so hard that I lose consciousness completely in about 10 sec. The only reason I'm alive to tell you about it is because it was a jail attempt and guards found me and cut me down in ~3 min. I hope some of that helps put your mind at ease...after a brief second of pain and confusion, I was out. I didn't even have to fight the survival instinct, after I jumped...there was never a thought or reaction to reach up and grab the "rope." You sound prepared, if this is what you truly want I would advise you not to overthink it.