Yeah, I didn't realize sodium nitrite is not regulated. I may go this route. Either that or a train currently.
But maybe I deserve to be stabbed. Maybe I could just use a knife and slam it into my chest.
Do you think you're worse than Samuel Little, a man who murdered 60 innocent women, lived to 80 years old, and then died peacefully in a hospital? There's zero reason to do that to yourself. You'd be pointlessly adding misery to the world.
Not to mention that it probably wouldn't even work- see graph. The SI's extremely intense, and even if you weren't found by someone you live with and didn't panic and call 911 yourself, your screams would most likely alert people nearby who would then call them. EMTs would probably save you. Then there could be massive medical bills, possible surgery, involuntary hospitalization, etc.
A train is also a bad idea- what it'll do to your body can't be predicted, so you might get mangled and live, and it's very gruesome either way- but even that's better.
Please look into SN as you're already doing and/or one of the top 5 methods above. Most anything else is a bad idea.