You're stressing for no reason.
First because there are so many ways to CTB that it's ridiculous to think that banning a substance will change anything.
Making SN or other substances harder to get won't change a thing.
People can jump, hang, drown, crash their car, poison themselves with pretty much anything...
I mean, what's the endgame? Ban windows, ropes, sea access, bathtubs, cars and 80% of products you find in any supermarket/store ?
I'm talking about legal ways here. Do you really think that someone who wants to OD won't be able to find Morphine, Fent and many other drugs knowing most of them drugs are available in either the streets or the DW since forever ?
Relax. I believe the contrary: there will be more ways to CTB available because research (individual or scientific) lead to better understanding of how our body works with molecules, chemicals, gases, and drugs. And as more and more people wish to die painlessly and with dignity, there will be fights (mostly legal) and results.