only married 9 months! Be glad you found out about it now and not 9 years from now. You are in the drivers seat. Take a good long read through so many of the posts here. The cold hard fact is he is most unlikely to achieve long term change. Prepare yourself for that eventuality. I completely understand giving it every chance you can. I've done the same. And I only received ANY movement towards sobriety when mine knew I was not kidding at the end. Once I had decided I would leave, she could sense it, and she knew she no longer had the power over me. I hope you can convey that message.
Before you get in too deep, just ask yourself how may second chances you're willing to endure. What ever the number, stick to it. If he can be one of the statistical anomalies and fix this on his own and now, then bravo. If he can't, then know you did everything you could and that is more than most would have endured.