Even though "as" is in the quote, your not really comparing yourself with your torn heart, so it's not a simile. However, this is an exaggeration because your heart was not torn from your body physically this is just how you felt.
well the "as" makes it a simile. its an exaggeration method used to emphasise a certain feeling or action. in this case its used to emphasise a feeling of grief or sadness. Hope this helps!
