What you are describing with the sugar high and then crash is normal. Best to stop that is to make sure when you eat something with sugar you also eat something with protein in it. The protein will level out the blood sugar and stop you from crashing. Also, eat small mini-meals every 3 hours or so.
OJ is a great natural sugar and gives you potassium. Take a good multi-vitamin because when our bodies are crying out for nutrients we can eat all kinds of weird crap! Lots and lots of water to flush toxins. I was told that for a alcohol craving, try eating some chocolate ice cream. Apparently the body processes ice cream much in the same way it does alcohol. As for gaining weight, know that you will level out and can address that issue then. I gained between 30 - 40lbs when I got sober. I just knew I was going to LOSE weight cause I wasn't ingesting the calories of alcohol but NO!!!
Anyway, I've lost about 25lbs since the first of this year and I have really done anything to do it. I think it is just the body trying to regulate itself.
Hang in there on the drinking thing. It will get easier, I promise. And keep going to meetings, they can save your butt!
Hugs,
Kellye