Part of the problem is that it's not a good idea to try one thing for a week and then try another and then another. It is confusing to the dog. When you put your hand over his muzzle, he felt threatened. He went into defence mode and threatened back. Anytime you "attack" your dog, you are risking a bite. I'm sure you didn't see it that way, but a dog does.
A puppy does not learn to not to nip, chew, teethe, jump up, pee in the house, get into your good stuff, be a general brat for a long time. He won't learn much in a week. You need to take the advice from experienced people or a trainer and stick with one program for a long time. Be consistant.
If a dog is receiving any kind of payoff, anything that makes it worthwhile to bite, he will repeat that behavior. If there is NO payoff, nothing good in it for the dog, the behavior will eventually extinguish itself. Your job is to figure out what the payoff is that he's getting. Why is he continuing to bite? (besides the fact that he is a pup and it takes a while) Are you looking at him, speaking to him, making a sound that he may be thinking is attention? Attention, good or bad is a payoff. Walk away from the dog. End all playtime. Give him a substitute chew toy and praise him for chewing that. Don't forget to praise him or he won't learn. Put him in a crate when you're getting to the end of your patience. Do not put him in when you're angry. Do not let him think it's a punishment. Just calmly remove him from you when you've had too much of him. Don't leave him there for too long of a time. It's not fair to him.
Another thing you can do, is start concentrating on giving him something to do....a job. He needs a job. Work on some obedience skills, a trick and make it fun, but not too exciteable. Get some treats. When he is "good" give him a treat. Is he getting enough exercise? If he's not a little tired out, he will tend to get rowdy. Make his day full...get him on a planned schedule. That helps.
Puppies are difficult. There's no question and they try our patience to the max, even experienced dog owners. But you can learn a lot from your dog and you'll be a more patient person when you grow up. I can almost guarantee it. Patience and education on training your dog will pay off in that you'll end up with a best friend who will be loyal to you....a rare commodity. Take 10 deep breaths and get back to work.
One more tip: (not that you're doing anything like this, just a general tip) Never ever mistreat your dog by hitting, squeezing, causing pain or fear. That is one thing that will surely ruin a dog and make him aggressive.
Obedience training, showing him things, asking for a sit, or down, or a paw shake before he gets a treat or his dinner or before he gets to have the door opened for him will let him know that you're in charge. That's how you let him know, not by harshness.
