Good job. But your punctuation needs some help. When you slit one sentence into more than one line, don't put a comma there unless it would be there if it was on one line. So
When you told me
what you thought was best.
or
Pain left searing in my heart
that pumps through my veins
like a virus; there's no escape.
Nothing ruins a good poem like stopping and the end of every line. Good job otherwise.