monophobia
/ˌmɒnəˈfoʊbiə/Definitions
1. noun
A persistent and irrational fear of being alone or abandoned, often leading to anxiety and avoidance of social situations.
“Her monophobia made it difficult for her to attend parties alone, as she would often feel overwhelmed by the possibility of being left behind.”
2. noun
A fear of being alone or abandoned, especially in a romantic relationship.
“The breakup left him with a deep-seated monophobia that made it hard for him to trust new partners.”