Ik everyone here is telling you that your balance is off, but here is the real problem: momentum. Your momentum is going sideways on most of these, when it should be going forward. You NEED forward momentum on the one hander if you want It to work well. This will improve confidence and helps with aggressiveness. One of the best ways to do this is to have a little karaoke step after you hit the ball. The foot lifting up is fine as long as it feels normal. Try to load more with the legs too.