o•ver•whelmed

Feeling completely overcome or overpowered by a situation or set of circumstances, often because there's too much to handle or process at one time.

Here are some aspects of what it might feel like or involve:

Emotional Response: A strong emotional reaction where one might feel anxiety, stress, panic, or even despair due to the perceived magnitude or complexity of tasks, information, or emotions.

Cognitive Overload: When the amount of information or number of tasks exceeds one's ability to cope or process effectively. This can lead to decision fatigue, reduced productivity, or mistakes.

Physical Sensations: It can manifest physically through symptoms like fatigue, headaches, insomnia, or a feeling of being physically weighed down.

Loss of Control: A sense that things are spiraling out of one's control, where even small additional tasks or bits of information can feel like the proverbial straw that breaks the camel's back.

Decreased Performance: Efficiency and effectiveness in dealing with tasks might decrease. One might start procrastinating or avoiding tasks due to the feeling of being swamped.

Social Impact: It might lead to withdrawal from social interactions as a coping mechanism, or alternatively, seeking help and support from others.

With help from @grok