One of our dogs was a Katrina refugee and a pit bull. Boudreaux was very aggressive when he first came to us. He is a very dominant dog and it was vital that I convince him that I am more dominant than he in our pack. We did go to training of a form locally called “boot camp.” It was quite intensive but was focused first on one basic thing: to get your dog to accept that you are his pack leader so what you say goes.
The second part of the training was concerned with teaching the dog to “speak” English; that is, to understand various commands and what they mean for him to do. The third part was working with the human to get them to understand how dogs think.
The result of this training is that if I tell him to “Leave it!” Boudreaux stops dead in his tracks. He might continue to growl lightly but he does not continue his attack. Boudreaux also knows to Sit, Stay, Come, Go outside, Get down, Get up, and several other commands. He is thoroughly bonded to me and will follow my commands. Of course, training didn’t stop when the class ended. It was important that I keep working with Boudreaux all the time, not just for a couple of hours three times a week.
I strongly suggest that you find a good trainer and work with the trainer to get your dog to bond to you, to get him to consider you to be dominant over him, and to make sure the two of you speak the same language.
Bully breeds can be wonderful pets in that they are bred to please their humans. However, you need to explain to them in ways they understand what it is you want them to do.