Mom wasn't tired of feeding - she was weaning. By leaving the litter at such a young age, your poor puppy didn't have a chance to learn much of anything regarding bite inhibition or doggy language at all.
If you follow the advice already given, you should be able to get through this. Having said that - it is going to take quite some time and patience. I also STRONGLY suggest you find a puppy class to get your puppy in at 12 weeks old - preferably with a positive reinforcement trainer - as you are going to need plenty of help and hands on advice in the months to come.