But I have a raya that you can say lashon hara about yourself.
Sefer Chofetz Chaim 1:9:
??? ??? ?????? ?? ???? ????? ???? ?? ????? ??? ?? ???? ?? ?? ??? ????? ???? ?????? ????? ?????? ?? ???? ??? ????? ??? ???? ???????? ?? ????
Now if it is assur to say lashon hara about yourself, then including yourself in the g’nus wouldn’t make it better; it would make it worse because now you are saying lashon hara about two people.
However, one might respond that this is not a raya because perhaps the Chofetz Chaim is not bringing this up in terms of the etzem badness of the issur, but because you might think that if you include yourself in the g’nus then you are demonstrating that you don’t really view it as something so bad. (Though it would be odd that the Chofetz Chaim didn’t mention that now you made the issur worse.)
And anyway, the source for this halacha is the Yalkut Shimoni in Isaiah Remez 406 which says:
????? ??? ?? ?? ?????? ???? ???? ????? ???? ?????? ????”? ??? ??? ????? ???? ????? ???? ?? ???? ?? ??? ??? ????? ???? ?????? ????? ?????? ?????? ???? ????? ?? ????? ????? ????? ???? ??? ?? ??????? ?? ????? ???? ??????? ?? ???? ????? ??? ??? ???? ????? ?? ??? ????? ???? ???? ??? ?? ???”? ?? ????? ?? ??? ??? ????? ???? ??? ?? ???? ???? ????? ??? ???? ???? ???? ????? ????? ?? ??? ????? ???? ???? ??? ??? ?? ??? ????? ???? ??? ??? ?? ?????? ????? ???? ??? ???? ??? ??? ???? ??? ???? ?”? ????? ?? ????? ??? ?? ????? ??????? ?? ??? ??? ??? ???? ?? ??? ???? ????? ????? ??? ??? ?? ????? ???? ????? ?? ??? ??? ???? ????? ????? ??? ???? ???? ?? ?? ?? ????? ?? ????? ???? ????? ??? ???? ?? ??? ???? ????? ???? ??? ??????? ?????? ??? ??? ???? ?? ?????? ????? ?? ??? ?? ????? ?? ???? ??? ????? ??? ?? ???? ????? ??? ????? ????? ?? ??? ????? ?? ??? ???? ????? ????? ?????? ??? ????? ?? ??? ????? ???? ???? ???? ?? ????? ????
I think it’s pretty clear from the medrash that speaking badly about himself was perfectly fine.