What BGfisher said.

Also, close up the distance to 10-15 yards and shoot at a small dot, like one of those orange sticky dots. Standing closer, your movement won't seem so bad. Aiming at a small dot will help you focus in better. When you've built up your strength and have got things holding steadier, then you can start backing up.

Don't beat yourself into frustration trying to do something you're not yet ready for!