I also could have written your post. When I stayed at home with my daughter, I thought I was going to go crazy. That's also when I started drinking heavily. Unfortunately, when I went back to work it didn't stop....it got better. My position was recently eliminated...making it worse. I think thats my biggest problem. I've had my teaching credential for 3 years and I still am just substitute teaching and taking long-term assignments - nothing under contract.
Maybe you should consider going back to work part-time - if it's possible. I fully understand how motherhood makes people feel like they've lost their individuality. It did the same for me. I wasn't Amanda anymore, I was Ava's mom. I love being a mother and I love my child more than anything, but I understand how you fee. I also resented my husband because his life seemed unaffected. We've had some marital issues and I've basically told him exactly how I feel and he's gotten better about helping out. If you haven't already, tell him how you feel. I know you said it's difficult for you, but he needs to know before you really start resenting him and possibly fall apart.
As for drinking responsibly. That would of course be my goal, but I always seem to get in the habit of daily drinking and even getting drunk most nights after my daughter goes to sleep. I think it depends on whether or not you're really an alcoholic. I've had many dependency issues, so I think for me it's all or nothing, but you can be different!