It sounds like he's becoming a 'teenager'. Pickles, who's always been the nervier of my pair, got pretty bad around this time. He calmed down an awful lot after he was neutered, although he still doesn't tend to enjoy being picked up. Some rabbits are just independant.
I would suggest you have your bunny 'done' assuming you haven't already, and for now at least, don't pick him up when it isn't necessary. When you want to spend quality time with him get down to his level, (he may have a fear of heights, or being constrained, and this is why he's biting). Feed him partly by hand to reinforce the idea that you are a 'good thing', and if he hurts you through aggression, rather than fear, (that is to say, he hops up to you and bites you, not just when you pick him up) repremand him with a sharp 'No!'.