Sounds like this is a very intelligent dog that really needs someone who can give 100% of their time. In fact this dog needs a job...this kind of breed as well as several others will act this way when they are bored. So many end up in shelters or worse put down because people unlike you have given up on them. I think you are amazing sticking it out this long! Don't feel bad about what you have done at all, but maybe use your energy in finding something useful for this dog to do. Not sure how dogs are recruited for police work...search and rescue, or even narcotic work but I would give it try. Good luck!
