Hi mnh1982,
When I found out my husband was using heroin his Father blamed me saying it was because I was not being a good wife! I had left for a month to travel for work (long story and when I left the relationship was fine). He was staying with his Father. When we reunited he had picked up, and his father said it was because I left.
So I think often people just don't understand addiction.
It's frustrating however no point in arguing.