I think it's a bit odd not to be comfortable with your husband seeing you change but he should 100% respect your request.
I think, given the OP's updates, that any uncomfortable feelings are as a result of the emotional abuse coming to the fore.
I, too, was very uncomfortable changing with my ex in the room. Had a lot to do with abusive behaviour; I didn't want to give him opportunities to make any more digs at me.
In the early days, it wasn't so bad. We did have mutual respect, so it seemed, we never invaded privacy when on the toilet, or bathing, or changing. In the final years, he would be vocal about expecting privacy when on the toilet, or washing, or bathing, or changing. Yet would barge in on me when I was on the toilet, or bathing, changing, etc. He refused to accept that I wanted privacy. He also thought nothing of barging in on our teen DD when she was changing, on the grounds that it was his house so he could go anywhere.
So, I wonder if people who are uncomfortable with partners around when changing, bathing, etc, are subconsciously reacting to any abusive behaviour.