Oh gosh. As an alcoholic with a totally sober partner, I'd say no, this isn't normal and it's not cool. The thing is, although I screwed a lot of stuff up through my drinking, I always worked overtime to meet my financial commitments and although I know that this isn't the case with every alcoholic, I also know that there has to be a line you need to draw.
Patience is one thing, but being financially screwed over when you have commitments is quite another.