It appears you mind is made up, that missing 10% is the natural doubt of ending things. When you have to choose from turning left or right, you will have that nibbling “what if I went the other way” but it sounds to me you’re justified. You spoke with him, he said he would change, but doesn’t seem willing. I would consider a couple’s counsellor to work through things and try to transition smoothly, but it sounds wise to walk away, or else you will feel worse.

All the best to you.