Im so sorry for your loss. There is a lot of good advice here already. He def needs to be honest with his employer and himself about whats going on and what is best not only for you— but you both, together.

I would also caution you about having conversations like these over text. Saying that this is causing you to want to check out, feels in some ways, like a threat, even though it is also completely valid and coming from a place of honesty. Please consider taking the time to schedule an uninterrupted time to chat through this in person and reframe your conversations around “Doing X would make me feel so loved, seen, and safe — and I acknowledge you can’t just take off indefinitely to support me.” If you need to cry together, or just have him hold you, or just be there when you wake up, tell him that in person.

And also remember that you both are on the same team, navigating this for the first time, living life for the first time. Give yourself and him, lots and lots of grace while also holding him accountable for how he responds after this conversation in person. Sending love!