Green’s Dictionary of Slang

(US campus) an expression of commiseration.

1993		Eble Campus Sl. Apr.
1996		Eble Sl. and Sociability 101: I’m hating it, I’m serious, sucks to be you, tell me about it, [...] are various ways of expressing commiseration in the face of misfortune.
2000		Eminem ‘Drug Ballad’ 🎵 Sucks to be you.