I believe there IS something to the theory about the more game you shoot the less nervous you become. When I first started squirrel hunting with a rimfire I got nervous as can be spotting, stalking, and aiming. Since then I've killed a ton of squirrels, and although I still enjoy hunting them, I'm no where near as excited as I was back then.
The problem with bowhunting deer is, I'll never kill all that many, so ....................
but, I don't get out much, but if you do, keep in mind, even if it doesn't get easy, you'll become less nervous. :D