You couldnt kill yourself with benzos if you tried.. unless you took a huge amount with a LOT of alcohol there is no chance of death, though you might pass out and not remember anything...
And Rohypnol comes in 1mg tabs and 2mg tabs (though the latter is now only available to hospitals) .. if you have a tab that says "Roche" and "5" I'd say it's a valium, but it certinly isnt Rohypnol..