心乱如麻 (xīn luàn rú má): To be extremely upset or confused — Meaning & Stroke Order

Faced with two choices, his mind was in a tangle and he couldn't decide.

The night before the exam, she was so anxious that she couldn't focus on studying.

She paced back and forth with a tangled heart, not saying a word.

After the breakup, his heart was in a knot and he was listless all day.