Crawl into (one's) shell American British phrasal verb
To become less interested in other people and less willing to talk and take part in social activities
Racism makes me crawl into my shell.
I used to crawl into my shell and took me years to get the confidence to talk in public.
If you disagree, please speak up. Don't crawl into your shell, no one can get your opinions.
The phrase starts with a verb, therefore, it needs to conjugate within the sentence. Besides, we should use this phrase in the appropriate context.