Greetings friend 
They are very important issues that we must know and know how to handle, the moyoria of us go through these existential crises. and it can happen when we have a problem and we feel alone, also when a family member leaves us for another country, when we die a family member, a disappointment in love there are many issues that lead us to these crises.
Greetings and thank you for your valuable contribution.
RE: Psychological education: How do we know we are going through an existential crisis?