

Given this definition: https://my.clevelandclinic.org/health/diagnostics/22327-differential-diagnosis
Your healthcare provider will compile a differential diagnosis, which is a list of conditions that share the same symptoms to help make a final diagnosis. The differential diagnosis will direct your healthcare provider to offer tests to rule out conditions and lead them to find the cause of your symptoms.
Seems one builds a list of other things that could be the answer. Then one rules those things out.
Seems a lot like building a hypothesis (ensuring it is falsifiable), and then proving it wrong.
Edit: In “Clue”, I make suggestions in the late game where I expect only one part is falsifiable.
Greif and loss. The first year is the worst.
Might be time to focus on processing the loss of your previous hopes, dreams, relationships, and projects.