He sounds like he needs more work on place. If you have not started to use corrections like a no and whatever type of correction he respects, then you need to start. Obviously, he doesn't hear you when he's in the zone nor are you strong enough to hold this dog back so you need to either work hard on following through with your commands or crate him. It's much easier and cheaper to crate a dog. The important thing is to stop his brain from escalating. That means correcting, redirecting when he's watching. When he's watching, the bomb is already ticking. My dog is one of those that cannot watch. He must be redirected, corrected or actively doing a command and I'm not one to jump first on using physical corrections, but in this case where the dog is a danger to other people and to himself, then the behavior needs to be shut down immediately and yes I would do the same to my own dog.