Separation is treated socially as an administrative event with some sadness attached. In practice it is a bereavement without a funeral — and one where you are expected to keep functioning throughout, frequently while still in contact with the person you are grieving.
It also disturbs identity. Habits, friendships, holidays, the assumed shape of the next decade: all of it needs rebuilding at exactly the moment you have least capacity for it.
Where the ending involved betrayal or the erosion of your sense of reality, there is trauma work to do as well as grief work. The two are not the same and need different handling.
How the work tends to go
Grief work for what has actually been lost, trauma work where the ending was destabilising, and — when you are ready — values work on what you want to build rather than what you are recovering from.

