Nietzsche, in the works you mentioned, and in addition, famously in "Also Sprach Zarathustra."
We shouldn't forget one of my favorite writers of aphorisms, Simone Weil, in "Waiting on God" and particularly in "Gravity and Grace."
And there's always Emily Dickinson, particularly in her letters.
There's a nice book out by two feminists ( not that their being feminists is the point), "Open Me Carefully", analyzing and detailing Emily's romantic attachment to Susan, her sister-in-law. The book is filled with a clever analysis of the aphoristic letters and the "coded" messages of affection sent back and forth between the two women, after Austin married Susan and they set up housekeeping next door to Emily.