I think you mentioned a very important point and that is that your trust has been broken. I COMPLETELY get it. It took me going to a behaviorist and having her tell me that my dog was not aggressive. Yes, there are things that I or others could do (unknowingly) to put him in a position where he felt he needed to act aggressively, but that was not his normal state of being.
For me, hearing that, was HUGE! His behavior was no longer random and it empowered me. I was able to become more aware and see what I may or may not have been doing that broke his trust in me. She was also able to give me tools to make him safe (namely a muzzle) and from there we could start to rebuild our trust in one another.
For us, it had absolutely nothing to do with obedience and everything to do with relationship. Three years and a lot of consistent work later, our relationship is rock solid, his behavior is predictable, and he knows that I will keep him safe - which is what he needed from me and exactly what I was not providing.
