I'm late to this as I haven't checked this sub in awhile but this post caught my attention...
Maybe he has something going on inside him; guilt about something ..maybe. More likely tho stress related to his job or finances or something maybe that impacts you that he's trying to shield you from, or is afraid to tell you about.
Yes, he still finds you attractive, yes he still wants to do you. Seems to me he's just stuck on a weird "pause" and feels like he needs to resolve something in his head or resolve soemthing in what he is doing for work or something. That's my gut thought on first reading. Of course I don't know either of you but I'm almost his age in a couple years and I know how work at this age can get kind of weird so maybe I'm transferring my own issues onto the situation. To be certain, I'm not saying he's cheating - just that for some reason it seems he doesn't feel he deserves to enjoy you right now for whatever reason.
Are you encouraging him in daily life? Do you talk about things and completely leave the topic of sex alone?
Whatever the case may be... communication is key and you won't get anywhere unless you utilize that to get to the heart of what is going on.
If there is something major and he feels that he can truly trust you with it enough to open up and tell you without you freaking out and potentially leaving him it will have phenomenonal results in all aspects of your relationship. Even if he opens up to say he thinks he might be or is gay or asexual or bi sexual or worried about losing his job or having physical problems that he doesn't understand and is too afraid/embarrassed/ashamed of to seek treatment for... no matter what the case may be - you know what... if he is talking to you abou it - that is the BEST thing that can happen. Growth, progress and CONNECTION.
He is your husband. Love him no matter what.
You'll be glad you did.
Do everything you can. as far as it depends on you, to make things work. If he doesn't open up, if you aren't connecting after trying everything you can.. Then you've done all that you can do.
In the end, with that self-less unconditionally loving efforts behind your belt - if he stays closed up and shuts you out - you should know that you've done all that you could....
and everything after will be fine.
I've been there before.
It works.
I know this to be true.
Hope that helps