You may feel like that because you feel more 'needy' due to your diagnosis. He may not see this as a problem, but rather as something he can help you with and through. If that is what he wants to do, to help you and care for you, then let him do that.

As far as feeling selfish, I would say like any relationship, concentrate on being a friend. Friendships give and take, and at any one given time, one is either giving or recieving. That is the basis of a good friendship.Take time to spend on him, his problems, his feelings, his needs and desires, and let him do the same for you.

Most of all, enjoy having someone to share yourself with