I got habituated to fiorinal with a half grain (32 mg) of codeine. Wow, is that stuff soothing! I didn't get to dozens per day, but probably only because I didn't have access to them, and like you, was prescribed them for migraines.
That was about 25 years ago. I became an alcoholic after that, but now, and for the last three years, it's been very good.
My advice is to simply stay the course - each day will bring improvement for you in some way. Be mindful of these improvements and you will soon become them. You won't regret a single moment of sobriety. Best to you.