WindGuru, I understand your plight. I recently ended a 7 year relationship and 5 year marriage that was much like the relationship you talk of. We spent all day together most days and made many many memories. I now find myself avoiding so many things because they remind me of him.
The only things that help are , like others have said, going outside and being around other people. That last one is not easy because it's hard to see others happy when we are so clearly not. I have also tried to find new things, things with no attachment or memories of him, like tv shows and movies and hobbies. I find a little joy in things that don't remind me and it gives me hope that I won't always feel this way.
I feel for you. It's not easy going through this. I can't say for sure that there is light at the end of this but I hope for both of our sakes there is. We just have to take it one day at a time.