This started a year ago, you say, so think back.
Something significant must have happened about then to cause this.
Could it be due to lockdown?
Once when I asked my husband what was wrong, it transpired he felt I had turned him down flat when he felt like sex. I had genuinely no recollection of the incident he was referring to. Finally, he accepted that I just had not realised what he was hinting on that day. It happened while my sister was dying, which probably contributed to my not cottoning on to what he really was saying.
Could your husband be feeling "put down" in the same way?
Can you get him to talk about what is bothering him?
Have you tried walking around the bedroom in whatever you know turns him on?
I am not trying to say this is your fault, but somewhere something has gone wrong, and if it is just a case of crossed wires then it pays to get it sorted out.
Sorry, just re-read your post and see you have tried to get close to him.
Have you also tried telling him that you are worried about him?
Finally, has anything similar happened earlier on in your marriage and how did you cope/ solve the problem then?
Not looking for an answer - it's none of my business, but might help you to find out what is going on.
Has his behaviour changed in other ways too?
Mysterious hole - help please!
To think that London, or anywhere else for that matter, does not belong to any one demographic
Should women have equal pay and opportunities?