to tie someone/oneself up in knots
to tie someone/oneself up in knots = too busy on one issue
和英辞書にも英英辞書にもいろいろなことが書いてありますが、
ネイティブに確認してみると
何かネガティブなことがあって
そのことにかかりっきりになっている状態を表すときに使えるそうです。
私自身も気にしすぎたり考え込んだりしがちなので
このイディオムは覚えておきたいなぁと思いました。
Someone told you something offensive. That upset you. You were always thinking about it all the day. Your brain & mind were not free to do anything else. Your husband told you, "I don't know why you're tying youself up in knots about it." Then you realized it was a waste of time. And you talked to yourself, "I'm not gonna tie myself up in knots about it. I'm ignoring."
