Low blood sugar the cause of my alcohol cravings?

In a straightforwards reply, I could suggest that you take the simple test for diabetes and that would tell you if you had a serious sugar problem. But understanding how the sugar metabolism works would give you better guidance:

Insulin regulates the amount of sugar available in the blood. If we take in a high dose of sugar, the insulin will shut down the sugar level in the blood, which is why we might feel not good a while after taking sugar, in fact we might get hungry all over again. Alcohol, and especially lagers and beers have large quantities of sugar, which produces this cycle of drop in sugar level in the blood which is relieved by more alcohol and more sugar. This situation is further exacerbated, when alcoholics stop eating and only drink.

However, my understanding is that you are not particularly suffering from this cycle as you are eating regular meals so you need to understand that regular drinking does create a pattern which is difficult to stop as the body becomes used to the level of drinkiing and all the habits around it. If you have been drinking habitually to excess, then you should get medical advice as to whether you can safely stop drinking or may need some medication to help you over.

As far as the eating is concerned, it is important to as you say eat regularly. Get a good proportion of protein foods and vegetables and keep sweet foods to a minimum. Eat before drinking and get some Vitamin B especially Vitamin B12 supplements. Sugar is important, eating properly is important, but what you really have before you is the choice between a life taken down by drinking and taking up life as a sober person. 

I wish you every support in the coming New Year and the positive changes you deserve.