Well, first of all, you cannot even expect from you to be able to correct everything in 5 days. It takes ages to really get consistent mechanics, and the formula is just practice, practice and more practice. Repetition is the key.
I'd agree with the solutions given already. Get rid of all the extra movement you can and keep everything simple. When you get consistent with the most simplified mechs, you can start adding high leg kicks and whatever turns and twist you like (little by little off course). But until you establish consistency, go with the simple slide step from the strech.
A tip I'd give to the slide step would be to get your balance point down, a.k.a don't just stand tall. Here's an example of what I mean.
For you, I recommend the same but without a leg kick (you can see Bonderman is finishing his leg kick here and starting his drive/push). Simply start sliding sideways to home plate and concentrate on your right foot and get as much sideway push and drive as you can, and then simply explode into the throw.
The lower you can get yourself without losing balance the better, but also remeber that this requires strong legs because you're crouching all the time, so I'd say try and see if this advice works for you. The stronger you kick/push yourself towards home plate the more momentum you get which results in stronger throws. So basically you're just ripping everything you can get from the simplest mechanics.
So well, try and see how this works for you. I also advice you to concentrate in the rythm, because when leaving the leg kick out of the equation it results in a much faster performance as a whole, and for some this might mean their arm action starts too late and they lose all the energy created with the drive too early and do not transfer it into the arm and all the way to the throw. So also sync your arm to the new, faster delivery.
I hope this helps you. Good luck to the game.