if nothing else go find a hospital... and tell them your situation, nitro is what they call "laughing gas"... puts you to sleep and so on... they may be sceptical about giving out the info but just make sure they understand the reason you need it and im sure they will tell you who they get it from... never know, but it would be worth a try if nothing else works...

doesnt tower ship world wide... im sure it would take some time for it to get to you since it wont be sent via air...