Big Dog! You'll get through it! It's okay! We almost gave up our Ranger boy too. He was the nippiest nastiest puppy. He would grab the back of your jeans (It was August, hot and humid, we had to wear the jeans or we would have stiches!) anyway, he would grab on and shake.
Binaca sprays, water, loud things, they all just made him more creative & sneeky.
What did we do? Here is a big list, sorry if some of this is a repeat.
One: Teething was the biggest issue. I started a very careful routine of only playtime after freezing his mouth for one. Get some Boda Rope Toys, or use old wash cloths, soak them in something yummy, freeze them. Let him chew it to bits, then go outside and play. While his mouth is cold and he isn't in pain.
Two: Many Many Many Many pressed rawhide bully sticks. If he tires of them wipe them with something better to get going. Cream cheese, peanut butter, etc. They need to chew to get out the urge to bite. Or it's just keeping his mind busy, either way, they were great! He wouldn't nip us for two hours or so after.
Three: Play Pen. We never used the crate as punishment, but we did use a play pen in our family room. If he acted inappropriately he went in there immediately. He was so bored, he calmed down. It will give you some space as well. I almost hit him because he nipped my leg. But because we had the play pen, I just placed him in there, and viola. I got the 15 minutes of space. Some will argue with this, I found it to be a great way to keep me from becoming violent towards a dog who didn't know the rules.
Four: A harness. Our guy wore a harness a lot so we could control him. He was like trying to catch a greased pig when he was feisty. But, the harness gave us the abilty to put our hand on his back and ... put him in the play pen!
Five: Carry a small toy at all times. Maybe for right now, this is the only way you pet him? While you are petting him, etc. Shove (politely) the toy in his mouth. Hold it in there while you pet him. If he's eating the toy, he can't eat you. (Of course, don't give a toy if he eats you first) Give lots of praise. End it quickly.
Six: Ignore him. We actually did the high pitched squeal followed by ignoring him. For instance... He was running, playing, etc. Everything was going well, then Bam! He's nippy! I would scream as if I was in serious pain, very high pitched. The scream was at the same exact moment his tooth was on me. Then I would immediately end play, turn my back and leave. The first few times he continued his antics. But, he got it eventually.
Seven: Give him something else to do. Occasionally you will see he is going to nip you, tell him to sit. I thought this wasn't working either, it will, keep it up. You are conditioning him. Eventually, he will run and sit. It may take six months for him to do the sit. But, he will.
Eight: Give him something else to do -throwing things far. If you see him coming at you, throw something. Not at him, for him to go get. Be it that toy you are now carrying, a jacket, or an apple, a towel, something to redirect his attention away from eating you. When he gets it, be happy, silly, and fun.
Nine: When he is that rude I would tell myself he has confused me with a sheep. He just doesn't know any better. They are bred to have prey drive to control stock. They don't know how to control the urge to use their mouth with humans until we explain, sometimes over and over and over. With a lot of love and patience, you will show him. He's lucky! Because he has the best mom in the world!