One thing that helped me was having a career that I am passionate about. That helped fill the hole. Not saying you have to find passion in your work...but find your passion for something - may not have to be another person.

I really understand everything you are writing about.
My x boy met me when I was sooooo down. I am much better and guess that is not interesting enough for him anymore - after 7 years. I thought, wow - I'm so much better and I get to share this with a great guy I adored...I did not get the chance.

I promise you that you will start feeling better everyday...you will grieve less and less.