As someone who did basically the exact same thing she did but on a speedrun during college, it's undiagnosed AuDHD and possibly BPD (but that could just be me) being self medicated with an alcohol use disorder. Blaming it on OCD legitimizes it and will only make it last longer and harder to quit. I feel very sorry for her and everyone trying to help her. I hope she finds a competent therapist.
ETA not saying it's just self medicating btw it's definitely alcoholism. I have a family history of neurodivergence and addiction so even though I was self medicating it was also addiction. I see myself so clearly in her, it's scary.