I liken your behavior to running into a brick wall, busting your head, and choosing to run head first into it again. You need closure, I get that, but for now leave her alone period no matter what. Acceptance IS closure because right now you are too emotionally rattled and addled to understand reality, or truth, nor seem to have any control over your impulsive responses that bring you more pain than answers.

You are correct, it's a battle with yourself between your heart and head in your mind, and unless you listen to your head and not your heart you will never get control of either.

Be cool, calm, and collected and get control of YOURSELF my friend. And before you say you don't know how, just stop doing what your common sense tells you is DUMB sh1t.

LEAVE HER ALONE, PERIOD.