Hello:
You wrote you can't tell your husband to stop driving, but you actually can. Also, a doctor can tell him that if you don't want to.
Don't wait for a scary near miss (what happened to us); it's just too dangerous. Time for you to take charge and just tell him how it's going to be for safety sake.
Perhaps buy one new car for both of you to use. If you're retired, you probably only need one anyway; less insurance to pay.
Good luck!