A new animal has invaded his territory. It's a natural response for rabbits to become territorial and be protective when this happens, especially when it involves a predator invading their territory. When adding a new animal to a family/home this is something that has to be planned for as it is always a possibility for the animals not to get along, not just with rabbits but with any animal. You will need to be very careful with their interactions. Not only can your rabbit cause serious injury to your kitten if he feels threatened enough, but a scratch/bite from a cat can contain very harmful bacteria that can be potentially fatal to rabbits.
The best thing would be to keep them separate, but if this is something that is not going to happen, then I would suggest you read up on how to properly bond rabbits with each other. If you understand how to bond two rabbits together, it may help you to come up with some ideas on how to help your rabbit get along with your kitten. Though there is no way to know if it will work since rabbits and cats communicate differently. Usually the best way to introduce a rabbit and cat is by keeping them in separate areas and gradually letting them get to know each other through a gate or partition.
Him biting you and others is called referred aggression. Again, it is a natural response for rabbits when they feel their territory is being threatened. He is only protecting his territory and his tension from this is being manifest in biting you and others. Usually this is not intentional and is just from the tension created from the situation. The only ways to resolve this are to either remove the kitten from the equation or to find a way to truly bond them so that your rabbit no longer has the need to protect his territory. You may have the best luck at this bonding attempt in your new place as it will be neutral territory.