Can someone speak loshon hara to themselves about someone? Or is another person required?
Answer:
There is no prohibition of lashon hara about oneself.
Nonetheless, it is not recommended to denigrate oneself – for many reasons.
Sources:
Shut Le-Chafetz Chaim (Rosner, no. 24); see also Chafetz Chaim 7:6.
It also stands to reason that there is no prohibition of lashon hara about oneself; the crux of the prohibition of lashon hara is a flaw in middos, and this flaw does not apply to somebody speaking about himself.