Eminem is celebrating another milestone in his recovery from addiction. “Clean dozen, in the books! I’m not afraid,” the star, Marshall Mathers, said Monday on social media, marking 12 years of being sober.As he’s done in the past, the 47-year-old mentioned in the update the phrase “not afraid” from one of his songs.It refers to his 2010 song “Not Afraid,” which directly addresses Eminem’s struggles