Here are the relevant lyrics:
> Through the pain, I remain the same
And it's gonna stay this way until the day that they stop me
Somebody, stop me!
'Cause I'm burnin' through the pages, faster than the speed of light
Eminem uses the word "burn" to convey the idea of moving quickly and intensely through something. In this case, he is burning through the pages of his life, as he races towards his goals and aspirations.