Although I agree with what you're saying, the philosophy isn't so clear cut; even some strands of libertarian thought recognize harms against oneself, but the "oneself" is in the future, and could be considered a separate person. By an extension of the harm principle, it could be permissible to illegalize things which cause harm against people in future - the sale of cigarettes, for example.

I'm okay with that if we take out public healthcare, handouts, etc. If you want to be an outcast, go ahead, but deal with the consequences.

By your logic the government should be banning sugar, forcing people to exercise, and on and on. Using the welfare state as an excuse for the government to control the private lives of citizens is pernicious to individual liberty at best, and totalitarian at worst. A safety nets don't exist to allow for the state to be an ever watchful and scolding parent, but rather to provide a floor so that people don't fall in to miserable situations.

Furthermore, the idea that one's actions in private, concerning only their own body, should make them a social outcast is laughably puritanical. Inclusion in society is about how one engages in the public sphere.