I would talk to him about the undercurrent you perceive and what you see as his attitude and have a discussion of how you fit in, can help him, what you all's long term goals are, etc.

I think we are pretty much raised with our attitudes about money and then we reinforce them as we work with money, etc. I know my husband is super responsible but worries about the future a bit too much.

Trying to help him, I work hard to word things the way he can "hear" them and I try to see what he is working toward/stressing about and complement him on how well he manages the money.

I thought of my own fears and how they were making me anxious and worked to get him to help me with them, he wrote a "book" about our money and investments for me so if something happens to him, I'll have a clue Sometimes I sit with him and work on the bills/investments and we have a lot of discussions about what he is doing and why, etc.

Just taking an interest in "his" money and bills, bills and money might help him feel a bit calmer and less alone? I have found it is quite easy and interesting to broaden discussion about an aspect of our money use or investments into a more interesting-to-me, broader conversation. It sounds like your husband needs to be comforted/calmed down about the money and helped to see there are other things he can look at, that the bills aren't going to go anywhere if he thinks/talks about something else