Eminem at his Oct. 15 book party in N.Y.C.
10/17/2008 AT 01:00 PM EDT
In a new memoir
, rapper Eminem recalls his devastating grief after the 2006 shooting death
of his close friend and fellow D12 rapper Proof.
"I have never felt so much pain in my life," he writes in The Way I Am
, which hits stores Oct. 21 and features dozens of personal photos, handwritten lyrics and sketches. "It was tough for me to even get out of bed, and I had days when I couldn't walk, let alone write a rhyme."
Eminem, 36 – who has been working on a new album
in his hometown of Detroit – also opens up about how he and ex-wife
Kimberly Mathers are co-parenting daughter Hailie, 12, teenage niece Alaina, and 6-year-old Whitney, Kim's daughter from a previous relationship.
"Kim and I have had our differences, sure, but things are good between us now," says the rapper (real name Marshall B. Mathers III), adding that the two have forged a "seamless" back and forth between their homes. "She's there holding the fort down – and she does an amazing job."
For more on Eminem's
The Way I Am – including an except, 14 exclusive photos and Eminem's comments from the book, and coverage of the book launch
– go to EW.com