when I say dicipline, I don't mean beating a dog. I mean training it right. tell him with an loud and powerful voice that what he has done is wrong. You can't just let him do all things. Dogs live packs. When we adopt dogs, the family sort of becomes the pack. As the owner, you are the one that is above the dog. By letting go through with everything, you are making him the boss. I have seen dogs not letting their people sleep in their beds, because they did what you are doing: not telling the dog where it's place is in the pack. The dog claimed the bed as his (because as a leader he deserves the best sleeping place) And he defended it. These are the moments when your behavior in training your dog hits back at you. It has happend to me. MY dog is very cute, but one day, when I started to dicipline him for eating away my lunch he was starting to bite at me. Luckily nothing happend, and I went to a professional for training. And now he is ok. The problem is, that dogs also have a huge problem of being the boss of a "human" pack, because they don't know what how to behave. My dog was in constant nervousity, and constantly loosing his fur. I beg you. If you can't afford professional training (there are non violoent trainings, they are harder, and you have to be even more consistent, but they are there) read a good book about dog training. This will benefit the relationship between you and your dog.
uhh its not very hard to teach a dog its the lowest member of the pack unless there's small children around.