Where I live you have to be legally separated for 12 months before you can proceed with the official divorce, though there is a lot of wiggle room on the the date you say you "officially" separated. I never had to legally file for separation but I was able to get some kind of temporary order that placed all the assets (house included) in my name only. I worked really hard to get myself financially stable. I opened a bank account in my name only that he never knew about, I called every credit card he had in his name where I was just an authorized user and had me removed from that account and started stockpiling money on the side. I knew that I couldn't control what he did anymore but I COULD control what I did. It became therapy for me to get myself more and more secure and independent.
And let me add one more thing, my AH has been clean and sober for over 2 years now. Our marriage is stronger than ever. BUT...I will never, NOT EVER, not ever ever ever, put myself in such a situation again that if he relapses or if anything else should happen in our marriage completely non drug related that I couldn't be out and on my own in 24 hours and be completely financially stable. I will never let myself be as dependent on anyone ever again. I love knowing what all I am capable of now. My AH's drug use nearly destroyed us and was without question the worst time of my entire life, but there was one silver lining in it and that was the change that I made. I love myself so much now, I'm so much stronger and for the first time in my 34 years of living I know that I deserve the best in everything in life and that nobody gets to treat me badly. You deserve all of that too, your kids do too. Maybe your AH will start recovery but then again maybe he won't, again you can't control that. Start worrying about what you CAN control. What "feels" right to you right now? Follow that gut, I have found in my life it rarely lies to me even when I want to ignore it.