I had some blood work done (privately) and had the following: AST 43 ALT 49 ldh 290. I drink heavily on the weekend. Is this likely fatty liver?

Not enough info. Liver enzymes aren't a reliable indicator of alcohol-related liver changes; they can be several times normal with minimal liver damage, or completely normal with significant fatty liver. In any case, drinking isn't a good idea in any case, but in combination with iddm it's asking for trouble: alcohol blocks the steps your body takes to recover from episodes of low sugar, and can cause fatal hypogl.