Hey Transform...
What you are experiencing sounds absolutely draining. I don't have any suggestions on why you are feeling urges, but a professional I'm sure could help you to sort out your feelings.
I honestly feel for you and what you are putting yourself through and I so hope you begin heal. You mention that you have been detaching, but it seems if you aren't speaking to him directly, you are asking him to explain his whereabouts, or looking up his ex. This I would imagine is torture for you. Did you get a chance to look into any free clinics today?