Fallen and bruised, my face hits the cold ground.

I feel the word cold is adding a hindrance to the rhyme pattern

Alcohol and cigarettes taint your fading breath,
Nicotine and Whiskey, you wreak of death.

in the first line above you have changed the pattern as the second and fourth line should be like the first line is cos the pattern is followed in rest of the poem leaving the third stanza

I`m leaving my memories of you behind me,
Step by step, my heart is finally feeling free.

step by step, here again you changed the pattern followed in the rest of poem. it should have something like .......... and.............. and you wrote step by step

except of these structural criticisations I found the poem well but you know this ruind the whole momentum and the feel of the poem is diminished

I would give you 4/5 and you should well keep in mind such intricate structural sequences and make a check

Take care

I loved the last line and will remember it for life:-)

Roxiee