My Kaji baby was like that. When I would get home from work or school, they would tell me how Kaji went on and on if he couldn't see me. It was weird since Kaji didn't want me to pick him up at all at the time or be near him. When I would shower, I would do as you did and take him in the bathroom with me. After a short time, Kaji learned to open the shower door. Scared they daylights out of me! One day I got tired of him being such a peeping Tom when I showered that I pulled him in. He didn't like that one bit.
as far as the crying, it eventually stopped. He learned that I always come back, it just took time.