Hi Foolsgold,
I think you are doing great. I wish I had had your resolve when my kids were little. I have nothing but admiration for you.
As others have said, I think your self -doubt is normal, I'm sure you will be a wonderful mum.
Speaking as a mum who was drunk every night through all her kids' growing up years. you don't wanna go there. There is not a day goes by that I don't feel horrified that I drank around my kids, and the problems it caused. It may be hard to keep off the booze but it's a million times harder to look back at that. Trust me, I know.
Stay strong. (((()))))