If you are anxious about failing SN and suffering organ damage heres a few things that you can do to avoid suffering the damage. (If the SN doesn't kill you, something else will.)
1: Before ingesting the SN, fill a bathtub with water. Once you faint, you'll be submerged in the water and consequently, there'll be no chance of survival due to the fact that you won't be able to bring yourself above the water because of unconsciousness. If the SN somehow doesn't kill you, instead, you'll drown.
2: Stand at the edge of a tall building (must be over 15 floors.) When you pass out after drinking the SN, you'll fall down the building, and die.
These might still make you uneasy about going through with ctb with SN but they comforted me, most likely will do the same for some other people. I would recommend the bath method more, all you need to do is book a hotel stay for a few days and you're good. If you don't have access to any tall buildings in your area that is also a reason why you should do the bathtub method.