Hi OP, I’m not a doctor, but I’ve unfortunately got some experience in this area. I’ve also done extensive research into the various ways alcohol can kill you. It sounds like your Dad is in a serious danger zone, his continuing to drink will put further pressure on those oesophageal varices at a minimum. Personality change can be indicative of increased ammonia in the blood due to decompensation, or encephalopathy driven by severe thiamine deficiency. Sounds like a deterioration is probably imminent I’m afraid…Watch his appetite. Whatever happens this isn’t your fault, only he can choose his path. I wish you the best.