Agressive behavior biting

Question
I have a 14 wk old german shepard female not neutered. She has had health issues tape worms round worms  coxsidia and ear infections. everything but the round worms are gone she is on her final round of meds we hope. The problem is the dog bites us non stop nothing has worked. even had a dog trainer over for suggestions. she attacks us and acts as agressive as any full grown dog I have ever seen fight. she is very difficult to subdue She has torn our clothes and drawn blood while biting me, my wife and daughter on a daily basis. we are afraid of serious injury. have owned shepards in past never had this problem. we are too the point of having to return the puppy. We have tried EVERYTHING so far e were told she was too young for traing for 2 weeks.

Answer
Training should start as soon as the puppy starts to pay attention to much after 6 weeks.  That is why puppies should go to their homes at 7-8 weeks.  

Young Labs, which I know best, and other puppies tend to very bad about biting. You see a litter of them, and all the ones that are awake are biting another one or themselves. I am not even sure they realize that when they are alone, if they quit biting, they would quit being bitten. At 3 to 4 months they are getting their adult teeth, and it seems they spend every waking moment biting or chewing. One thing you can do at that stage is to knot and wet a piece of cloth. Then freeze it. The cooling will soothe the gums. Only let the puppy have it when you are there to watch it. I maintain a Lab's favorite chew toy is another Lab. Otherwise they settle for any person they can. They keep hoping to find one that won't yelp, jerk their hand away, and leave.

You just have to keep on correcting them, hundreds of times, not dozens. Provide sturdy, safe toys such as Kongs and Nylabones. Avoid things they can chew pieces off and choke on them. Keep them away from electrical cords. Crates are essential for most young Labs and other dogs.

The pet stores are full of toys that many dogs will quickly chew up into pieces they could choke on or cause intestinal blockages. If you are not there to watch, stick to sturdy stuff such as Nylabones and Kongs. Keep a close eye on chew toys and quickly discard anything that is coming apart in pieces. Rawhide is especially bad because it swells after being swallowed. I don't trust any of the consumable chews. The dogs just gnaw them down to a dangerous size too quickly. These problems are the worst with, but not limited to, large, aggressive chewers such as Labs.

The longer a puppy has been allowed to bite, the longer it will take to stop it.  Nothing will stop it right away.