Losing a close friend is a bereavement with no funeral, no acknowledged status and nobody asking how you are. That is why it lasts.
There is no word for the ex-version of a friend, no process for ending it, and no obvious permission to be upset. People are often surprised at how much a friendship costs them when it goes wrong, and then embarrassed at being upset by something they think should not count.
What people bring
A falling out that was never resolved. A friendship that has become one-directional. A friend whose behaviour you have been managing for years. Drifting apart after a move, a baby or an illness. Loneliness in adulthood, and how difficult it is to make friends after thirty.
What counselling offers
A place to work out what you actually want: repair, distance, or an ending you can accept. And to look at the patterns underneath, which usually turn out not to be about friendship alone.
Sessions are individual and typically fifty minutes.