woodenmeow, These symptoms sounds very much like ADD.
His problems sounds very familiar to my situation. Commitment issues, trouble focusing, love of projects but not always finishing, feeling like roadblocks and fog.
For me the biggest life changer was getting officially diagnosed. So This is my greatest advice.
I feel getting the official diagnosis helped me realize who I really am and my strong/ weak points.
Even without medication I could see more where I could fall into my bad behavior and try to prevent it from happening (a little bit more).
Since last month I started medication (strattera) in the hope to be a better husband and father but the positive effects have not really started yet…
Make him realize that he probably has it and if he want to get a bit more normal life he should get officially diagnosed.
This should (In my opinion) be made very clearly and strictly because otherwise he may not realize how much trouble he is really causing you and would continue to give you if you would like to stay together. I felt always standing against a wall and my wife needed often to use a big hammer to break down that wall and to open my eyes. Its very shocking and stressful, but those moments changed me for the better.