dogs chew to ease anxiety and to relax, so make sure there are plenty of toys for your dog to chew. you need to teach the dog “off” and reward it with treats for not chewing you . if the dog bites you , you should tell it off but never hit it. if it keeps biting you should nip the dog with your hand to simulate a bite to let it know who is boss.
we recently took on a 6 month old rescue dog that is very nervy and tried to bite and chew whenever it was anxious, but with a few one on one obedience classes with a local dog trainer he has improved amazingly.money well spent