Even though I totally know it's not right at all it seems impossible to have to tell everyone, and even though he knows things are crap he wouldn't want this.
You don’t have to tell everyone.
First you need to tell him.
Then you need to select 2-3 people to make it real. Your parents, a sibling or best friend. You can ask them to tell others if/when it comes up.
It is also not fair on your DH even in the short term. He needs to accept that you are not compatible - you don’t need to blame each other.
Not one person on here has said stick it out.
Again everyday you stay is for some miss-placed external image around shame.
Never live life in FOG (fear, obligation, guilt) - it is not honest and will eat you up from the inside out.
You can make a swift decision and move on now. Or you can put both of you through months and years of pain, it will turn ugly and toxic and will be the same outcome anyway. He has already started to treat you with contempt. Don’t let it go any further.
Have some dignity for your self and some respect for him and part now with honesty and kindness.