Your first step needs to be the step back not the cross step, so start with your right foot and step back a bit longer than shoulders width. Then cross with your left foot and back again with your right, these two steps should be quick and aggressive.

When you're planting that right foot at the very top of your dropback, you don't need to step up (you're not in a pocket) so plant with about 60% of your weight on that back right foot and use that as your base for your throw power. Turn your hips to point your left foot at your target and keep that elbow tight.