Training teach him what is allowed. Don’t train when you are angry. Training must be done matter of factly. Flat collar with a short leash. Use leash pressure straight up, do not jerk him just pressure up until he submits and sits calmly. Immediately say yes or good and reward. Remember they have a very short attention spans so you must Mark and reward behavior quickly at first. As they get older you can teach longer moments of being calm. Biting will get worse before it gets better. Teething is a hard time. We freeze rags then when they get nippy, give a negative reinforcement marker then allow him to bite the frozen rag. Play tug with him but not hard let him dictate the tugging. It will get better just use his drive to train him.
