Michah,
No words will ever help ease your anger and pain, though I wish you to know I am so sorry for what your family is going through. Hold on to your anger and pain only as long as it is needed, then you will be able to let it go. I pray that you and your family (his gf included) will, in time, heal and know that it wasn't about any of you, it was about him. I wish you peace.