Yes. But there is also an antiemetic available OTC: Diphenhdramin(e)(chloride, sold with different brand names worldwide.
Benzo OD usually don´t work. But there are other methods in combination with benzos:
Translation from German "Selbstbestimmt Sterben - Handreichung für einen rationalen Suizid (German Edition) Jessica Düber Amitriptyline guide "Tricyclic antidepressants General info Tricyclic antidepressants are psychotropic drugs with a general mood-lifting...
sanctioned-suicide.net
Translation from German "Selbstbestimmt Sterben - Handreichung für einen rationalen Suizid (German Edition) Jessica Düber Chloroquine "General info Chloroquine is a drug used for the treatment and prophylaxis of malaria and for the treatment of rheumatic diseases. Cause of death in case of...
sanctioned-suicide.net
This is just general information. I do not encourage you to commit suicide and to use these methods. You act on your own responsibility.
----
Sk3le, I missed your message.
E250 doesn´t tell you anything about the grade and purity.
According to the labels you (unfortunately) posted, your SN should be ok (purity 98%, NaNO2 is right).