Thanks unicorn

I really am glad I found this forum, I hope I can find some too.
I do take a kind of parental role with my sister, yes. I'm the youngest child, but I have always looked out for her from a very young age, so it's easy to adapt and set boundaries in that sense, because I'm kind of used to it in a way. When we were both teenagers, my sister and father took their rage out on each other, I always was the voice of reason with her because otherwise it would've ended badly with people getting hurt.
My father is an alcoholic, and when he becomes drunk it triggers his uBPD significantly. He can function quite well when he is sober. He is also alone for the first time in a very long time, which he doesn't like. He's tries to manipulate me to get attention because he doesn't have any other family really, and a very small network of friends who aren't very close to him.
I however have made it very clear I am not interested in speaking with him when he is in any kind of drunk state. I grew up with it as a child, and I do not agree with it at all, and refuse to put up with it. He recently has been binge drinking however and so as I do, I ignore him and let him know I'll be in touch when he is sober. He took things to extremes however due to taking himself to hospital because he knew the attention it would bring him when he calls and says "Im in hospital, give me all the attention I want" I knew when he called, he was fine... just drunk and triggered, and the doctors confirmed my beliefs within a few hours.
He regularly calls me each day, wanting to talk and wanting to know when I'm going to visit him. It was a lot more difficult to realise how manipulative he was when I lived at home, because I just thought as a parent he had the right to know what I was doing in a sense, as I was living under his roof. Politeness, is polite. However, now it's just excessive, and he uses all opportunities possible to get a reaction and get attention.
I feel bad for him in some ways, but in another sense... .I have no sympathy at all for him and just wish to be left alone. I am in contact with a member of my family and some other close family friends, and I've been trying to get them to be involved and give him some positive support when he's behaving appropriately (that sounds awful, but it's true) so that he can have some kind of support network.
Buuuuuut really, he's an adult, who I have little respect for the majority of the time... .and I want to put boundaries in place, so I can still have some form of relationship with him, because I know what a lovely person he can be, when he is in the right place... .but I'm a bit over it.