You're rubbing salt in my wounds

I thought it was bad before I met you
But this is something I didn't foresee
I've committed a deadly sin
By thinking you cared for me

My error, my mistake
I perceived you had a heart
Little did I know my fault
Would tear my life apart

Everything is lost
And my life is close to gone
Too late for me to know
You were the devil's spawn

I can't believe I was so foolish
Can't believe I was so dumb
You're rubbing salt in my wounds
And yet my body still feels numb