What would be the correct latin/greek word for it?
Melanotrypophobia, although the Greek term is "mayri trypa", literally "black hole".
Any relation to the words melancholy?
Yes, as the sibling said, melancholy means "black bile".
Yes, that is cognate with ancient Greek μελαγχολία, and with the same root: μέλας
https://en.wiktionary.org/wiki/melancholy
Hypochondriac
Melanotrypophobia, although the Greek term is "mayri trypa", literally "black hole".
Any relation to the words melancholy?
Yes, as the sibling said, melancholy means "black bile".
Yes, that is cognate with ancient Greek μελαγχολία, and with the same root: μέλας
https://en.wiktionary.org/wiki/melancholy
Hypochondriac