My guess is you aren't putting consistency first. You're working really hard on your mechanics, trying to play like the pros, but even the pros put consistency first. Watch a video of Rafa Nadal hitting in practice, and then watch him play a match. He plays it much safer in the match, and he's not unique at all. If your goal is to win, don't attempt a shot you aren't confident you can make. An analogy would be that a groundstroke is like a second serve. You can't allow yourself to miss more than the occasional groundstroke, even if that means hitting it slow and safe. As you progress with your technique, you'll find that you can swing out and keep the ball in, but you just aren't there yet.