Is something wrong, ethically, with self harm? You hear people say things like "do whatever you want, as long as you don't hurt anybody else." But, what if the person you are hurting is yourself? Is that ethically neutral? If you think so, your moral focus is on your relations to others.
In real life, self harm typically does harm others, too, at least indirectly.
But is that the reason self harm is wrong, or is it just one reason self harm is wrong?
Or you can stand this on its head, and argue that the reason harming others is wrong, is that it harms you. You should be forming your self into a person who deals with others on a win/win basis. That is the kind of person who thrives and is happy.
Out in the real world ethical map
there's lots of value overlap.