"blues songs that talk about the reality of being a blues singer"

What do you really expect? Hard traveling songs, stories about bad experiences on the road, discrimination? If so, there are a lot of songs.
Moreover, although I do like CCR this could be a misleading example because they are/ have been white people. No comparison to what problems black artists have had in former times.

Don't want to tell you all of these songs, but here'e a fine example: Traveler's Blues by Lightnin' Hopkins ( Verve)

Manfred