Agreed! You need a personal inhome trainer to help you get this behaviour under control. They will be able to see what you are doing wrong, and what you are allowing him to do...and then help you correct things.
Once you have a handle on this at home...you will benefit from a group class...so that he learns to listen to you under all sorts of distractions.
I am honestly worried for you!
This dog seems out of control. Has he bitten anyone or you yet?
I just took a look at the training website that you posted...and I think dogs doing Schutzhund training must be of sound mind?....you cannot take a dog that is out of control...and start training without any obedience background. You need to get your dog into the basics...just normal control and good manners.
Get help ASAP!
Gina