Biting frenzy 11 week old puppy

Our 11 week old Cocker Spaniel puppy goes through bouts of basically attacking me. barking, biting my arms legs and hands. I try to stand very still but it’s very difficult when he bites, at times drawing blood. I have stopped wearing anything that is loose fitting but this morning he bit me through my jeans. It really is frightening. I put him in his crate when this happens but he is almost feral and doesn’t settle. There is no real pattern to his behaviour. He has his 2nd vaccination on Thursday. I hope things will improve when he can go out for walks.
On the whole he is very good and settling in well. We have had him 7 days. Any advice would be greatly appreciated.