Three short lines sketch a person living on the street, and the poem puts us inside that person's head. The first image, "the ice in my head," suggests numbness: a mind frozen by cold weather, or by exhaustion and despair, or maybe both at once. Thought itself seems slowed down and hard to reach.
The second line is the strangest. "Alone with my account" could mean a story the speaker has to tell, a tally of what has gone wrong, or even a bank account that is empty. The ambiguity is part of the effect. Whatever the account is, the speaker faces it with no one else around.
Then comes the last line, "where I beg," which gives the setting a blunt, practical purpose. Begging is where the speaker's life gets spent. The mood is bleak and quiet. There is no self-pity or explanation, just a flat, clipped voice that makes the isolation and the chill feel complete.