Addiction is a beast that will do whatever it can to protect itself. It's sharpest tool is denial. An alcoholic in denial will blame whoever or whatever for their problems, and push off responsibility for their actions and choices as long as they can. Will this manifest as anger sometimes? Sure.
That being said, no one here can tell you whether or not you are blameless in the relationship. But we can guarantee you did not cause, cannot control, and certainly cannot control her alcoholism.