Hi Miller. Welcome to Soberrecovery.
My qualifier also swore up and down that he was done. I absolutely believed he wanted to be done but also didn't believe it was that easy. I left him and he eventually spiraled down.
Generally, it is recommended to give it a year. It is possible that this will work for him but highly unlikely.
Have you tried Alanon for yourself? Also the book Codependent No More is a bit of a bible around here. You might give it a try.