He’s a veteran and has been diagnosed with Dementia.
Take his car keys and unplug the battery in the car. You may think I'm joking, but no matter what an attorney tells you (contact DDS, call the police, etc.) the only thing that is going to physically stop him from driving is going to be making it impossible for him to do so.
You may want to consider filing for an adult guardianship in probate court. If his condition is bad enough, this may warrant you taking guardianship in order to make decisions on his behalf, including turning his driver's license back in to DDS.
In offering suggestions to you through this forum, I take no responsibility whatsoever for any course of action you do or don't take. I am providing you a courtesy only.
If you have proof of the dementia, you can always go talk to the Department of Drivers Services (aka "DMV") about his license and seek their guidance. Of course if he's the bread winner or drives as part of his livelihood, there will be economic consequences. But the alternative of serious injury to you, your kids, your husband and innocent people on the roadway is far too egregious to not to do something.
BUT for God's sake if he's an immediate danger of injury or worse to himself or anyone else on the roadway, call 911. If you have children don't let them in the car with him. The State can and will take them from you too for endangering them and the police can arrest you for neglect.
If you're thinking divorce, I can help.