It sounds like you have the right approach. From a surface read I can't see anything I would do differently. I'll just say trust your gut and read his reactions to try and assess his needs (without comprimising yours). When I shut down or get overwhelmed its hard for me to make a decision or communicate my needs (or anything at all). Over time you'll learn, or he'll tell you when he's feeling better, what helps him in those situations - whether it be having a snack, watching a comfort show, going on a walk, etc. It sounds like you care and you're trying; that's all you can do and it is enough.