ochikomuoちこむchikomu
1.

To experience a significant decline in mood or motivation, often triggered by disappointment or stress, resulting in feelings of sadness or hopelessness.

2.

To find oneself in a difficult emotional state characterized by a lack of energy or enthusiasm, typically following setbacks or unfavorable circumstances.

3.

To undergo a marked decrease in performance or success, particularly in a context where progress was previously stable or improving, leading to feelings of distress or concern.

4.

To fall into a metaphorical pit of despair, feeling overwhelmed by negative thoughts or situations, akin to being trapped in an emotional low point.

Example:

ちょっとしたことで直ぐに落ち込んでしまいます。