No doubt you will look back one day and be okay with things. It sounds like you did your best to salvage the relationship. I think it is a bit unfair that he says he'll ruin your life if he stays, even though you say he won't. It would be easier to deal with if he just took ownership of his feelings and got to the real reason. It would probably help you find closure more quickly. It might be more painful, but leaving things unclear and hanging really delay closure and probably make you think too much about what you could have changed or why he left.

I wish you luck in getting over him and coping with your other issues. I read a great inspirational story once about a child who sat at his Mom's knee while she embroidered a beautiful design. From underneath the embroidery hoop, he saw chaos of all these colored threads and knots that criss-crossed and didn't make a whole lot of sense. But when viewed as a whole from the top, something beautiful (someone's life) was being created. So, sometimes things seem terrible at the time, but other things happen and it all falls into place. Best of luck to you.