Time for a serious sit down with him. That's just not good enough. He put you in the position of needing the security of having full access. He needs to man up and follow through with your requirements. He's lucky to have the wife that comes with those requirements!
The circumstances that required him to change his password may be on the up and up but he needs to be more responsible with your feelings and your healing process. Once you explain it a time or two ignorance or lack of time is not a valid excuse.
The fear is that if you give an inch he may eventually take the mile.