This is a difficult situation, and the feelings that you are dealing with such as confusion, fear and even perhaps regret are hard to process and sort through. However, one thing is clear. Your husband is still living in a drug induced world. As long as the alcohol has him, nothing else can have him, and that includes relationships of any significance. Simply, he is far from ready to commit to any relationship and the long history of addiction and abuse that he has is still, very clearly, present.
I respect that he wants to try. However, trying and doing are two very different things, and most people with your husband's history take years to work through the cycle of addiction and abuse that he has allowed to impact his and your life.
He is not ready for you and I can only see pain and hurt and difficulty in your life if you would choose to be with him now.The final choice is, as always, your own. But, here, even with wanting to change, that is a far cry from actually doing so...
I would continue to try ti receive support via a professional counselor if you could. This can be confusing and ongoing support is always a benefit. As iron sharpens iron another unbiased perspective can help. Here, in this question though; from what I can see, the answer to to keep your distance. He needs to show, much more what he has said to prove that he is different, and I would highly recommend extreme caution in any action that moves you back in to a relationship with him. Steven