That’s completely OK, and not your fault. In your case, your sex drive towards your husband has changed due to a situational factor. This is the degree to which the sex drive is shaped by social, cultural, and situational factors.
The question is how? First, it’s important to understand the concept of erotic plasticity. I tend to feel we can work through sexual difficulties with respect, honesty, trust, and compassion, as long as the love for each other is there. The good news is, in your case, the love is real and transcends that aspect of your life, changing only your dynamic in the bedroom. Others have to work through a shift in how they spend their free time, if they aren’t constantly out at the bars. Some couples have a rude awakening that they don’t have as much in common without the partying component. That said, it can definitely change the dynamic in a relationship.
Getting sober when you know your life is out of control is a courageous and brave accomplishment. I want to first congratulate your husband.