Hello, my 63 year old dad is acting increasingly erratic. My mom passed away 4 years ago, and I know he is still grieving but I have no clue how to help. My dad is addicted to oxycodone/oxycontin, xanax, valium etc. He also drinks. Before my mom passed away this was a problem. Now it's just made worse. My dad drives with all this in his system and sees nothing wrong with it because "the doctor prescribed it", He is isolated and becoming more antisocial. It's gotten to the point I don't like him around my kids at all because he's so mean to them when he's coming down off medicine. I am an only child with literally no family other than my kids and my husband around. I have no idea where to go for help. I feel bad for my dad being so lonely but he's either a real jerk or out of it. I am unable to really even have a conversation with him anymore.
Other than that all you can do is detach from him. You don't need to have that kind of tornado roaring through your life or the life of your family. Deal with him as little as possible. I'm assuming from what you wrote that he lives alone.
There's nothing we can do about the alcoholics/addicts in our lives. We can't get them to do anything. They can't be forced. All we can do is take care of ourselves and how we deal with it.