This has got to be one of the toughest things to go through. 6 years is a long time. There must have been some good things in the relationship for it to have lasted that long. Despite that, you don't see this as salvageable. That puts you in grief. I ended a relationship after 4 years, and I felt confused and went back and forth on deciding to do that. You have to remind yourself of why you needed to end it. Keeping apart is probably the best way to get past the pain, which initially can be awful.