Its sounds like you love your dog very much, however, im sorry to say its not enuf just to love your dog, they must have taken him  for a reason. if you truly love him, and you know he is being taking care of, you should let him go, i know it hurts but its for the best, if you are unable to let him go, i would fix up your home to provide a good living space for him and take classes in dog behavor and training then contact the group with proof and letter of refrance from each course and invight them into your home, they may give him back seeing how much you do care for him, some poeple dont mean to hurt them they just dont know, but the only chance of getting him back is to know.