60 mg of Ativan may seem like a lot; in actuality, it's the equivalent of just over half a gram. Combined with Vodka and this would likely result in you vomiting (empty stomach or not), and having a terrible hangover when/if you do wake up. I say if, as there's always the possibility of passing out and vomiting while unconscious, then choking to death.
I've heard a story of a woman who overdosed on Alcohol and Seconal and died. Now, Seconal is a LOT more sedating than Ativan. Wish I had some, tbh. Unfortunately it's rarely prescribed, if at all, anymore.
In the past, when I had thoughts of ending my life in a similar way, I planned to duct tape my mouth, so I wouldn't be able to throw it up. Vomit would likely come out the nose though, and ultimately I researched other methods.