Dave,
Remember, "patients is a virtue." If it's meant to be, it will happen. Visualize the moment in your head beforehand -thousands of times (it's mental practice). Hash out what you intend to do. Run several scenarios. Bring yourself into the "zone". If you prepare this way, and when the moment is upon you, you will find your sub-conscious and instincts will take over (we'll be calling you Mister Automatic). When and if your heart starts racing-you feel yourself slipping-Slow Down! Close your eyes and get control! When you've regrouped, open your eyes and re-engage! It's better to have the memory of a missed opportunity than the memory of a wounded elk shot in haste or panic.
I'm in your corner....cheers!