It does feel pretty unbearable to lose a major war, specially if your own country is invaded and devastated during that war and specially if you have given your all for your country. Many German soldiers and civilians committed suicide in the last days of Nazi Germany. Many Japanese also, needless to say, killed themselves in despair when they found they had lost the war. It seems unbearable at the time, and there's a deep grieving process that people go through. Then you start rebuilding, and life resumes.

Many nations have gone through this. The southern states of the USA went through it in 1865. The northern and most of the western states have never gone through it.