Okay, nobody will care but I wanna say it :
Neeko is gifted. She didn't have to struggle much when she was in a scholar environment, hence she took everything "easy" to the point of not taking some very important parts seriously. She didn't apply to part-time jobs for that reason.
Basically, she got hit with failure after failure on an important part of your adult life, a first for her I believe. Depleting your motivation and self-esteem as you start to second-guess your every decisions. "If I had done X or Y back in the days instead of doing Z" "I shouldn't be struggling, it's something everyone can do!" "Maybe, I'm not made for it..." She gradually despaired and was on her last leg.
That last interview with the garbage company just destroyed the last drop of motivation she had for the "working adult" life.
Also, hair turning white... I remember when I was struggling alone on another continent because of University... I had no beard and yet I had white hair on my chin from the stress. So I can relate to her a lot.