I think you misunderstand. It's not necessarily about letting him know where you are and what your doing. That can be monotonous and it's not something I would need or want to have to know from my W.
You have to let him know he can count on you if need be. That you are there if he needs you. One thing a LBS feels when S has an A is abandonment. You start to realize that the only one you can count on is yourself. You become very independent, self sufficient, and somewhat protective of your affections. That's the mind set you might be dealing with. You have to show him you can enhance his life with your presence. Do things he isn't expecting, but adds value or comfort to his lifestyle. Little everyday things that show him he's important to you. That's how you build trust. I wish I could give you more specifics, but everyone has different emotional and physical needs. I would suggest reading "The 5 love languages" by Gary Chapmen to find out what needs your H has.
He needs to look at you as a partner he can trust again. It may take some time.
"It is curious that physical courage should be so common in the world and moral courage so rare." -Mark Twain
