You're stuck in a time warp from 2004, though

from Eminem – Rap God Lyrics on Rap Genius

Meaning

2004 was the year Encore dropped, an album which received mass criticism with claims that his music wasn’t up to par with his previous work.

Considering in the preceding lines Eminem addresses his position in the game, this is Em acknowledging 2004 as his personal artistic low point, which he admits is when the drugs started to affect the music and he was high in the studio. According to Em, Encore is an album he is most unhappy with out of all his work.

Encore was also his last album before his hiatus.

Effectively
He is addressing all fans and critics:

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