If you are looking for a way to describe feeling trapped or closed in, there are plenty of synonyms for the word "claustrophobic." One option is to use the phrase "enclosed space anxiety," which explains the feeling in more detail. Other synonyms include "confinement phobia," "intimacy aversion," and "containment distress." You could also describe the feeling as being "shut in," "boxed in," or "hemmed in." Another way to convey the same idea is to use the word "suffocating," which implies a lack of air or space. Regardless of which synonym you choose, they all convey a sense of feeling trapped and uncomfortable in close quarters.