The only people who are “fine” immediately after getting out of a relationship are the ones who were responsible for ending the relationship.
And the only reason they are “fine” is because they already grieved the loss of the relationship before they left.
They had been through the process of being unhappy, and deciding whether they should leave or not, and they already struggled through all of the emotional stuff before they decided to pull the plug.
Ultimately they were in control of ending the relationship because it was their idea.
The person who gets dumped doesn’t have any control because this wasn’t their idea.
The situation is suddenly thrust upon them. They still wanted to be in the relationship, and in one moment it is taken from them.
These are the people who aren’t “fine” immediately after a breakup. They didn’t have a chance to adjust to the idea of being without the other person like their partner did.
For many people, dealing with the unexpected loss of a relationship can be as hard as dealing with the sudden death of a loved one.