Why is Teddy so vicious?

Teddy my hungarian sheepdog- (puli) is REALLY EXTREMELY VICIOUS. Well, i am over exaggerating just a little. He IS a puppy. And he IS just teething, but he like- ONLY chews on ME. My mom, anyone, he doesn't chew on them, he only chews on ME.! He runs to me after i come home from school at 2:00 and he pounces on me snarling biting and pulling at my Socks hands feet legs, ANYTHING! My legs and hands are practically covered in bite marks, deep scratches and cuts. My BFF asked me what happened to your legs and arms, i said -TEDDY, teddy is what happened. She said- you should really get his nails cut if they are doing that to you. i said no, its not his nails, its his TEETH. I have tried everything from saying NOOOO in a very stern voice, to spraying him gently with a spray bottle, from grabbing him by the shoulders and shaking him sternly every time he bites me. I HAVE TRIED EVERYTHING! I CAN'T EMPHASIZE HOW MUCH I HAVE TRIED. And he really hurts my legs too! i dont want all the guys staring at my legs all day and wondering what the **** happened to me. I am not wearing long pants on days like 80 degree days like today to cover up the scars. He is so cute he is a little fluff ball and everyone thinks so, but i know what he really is. he is a... DEVIL PUPPY! How do i end this behavior.??? I really need help with this...