After my husband's death, I walked around in a daze like a zombie.

Literal

Husband's death-after I [topic-は] zombie [like-のように] aimlessly was-walking-around.

ゾンビのように = 'like a zombie.' ふらふら is a 擬態語 for unsteady, aimless wandering. 歩き回る = 'to walk around.' A vivid depiction of grief-induced numbness.