。
She was terribly cold toward me.
Literal
She [topic-は] me [to-に] terribly unfriendly was.
不愛想 (ぶあいそう) — literally 'un-amiable' (不 'not' + 愛想 'amiability') — is a na-adjective for 'curt, brusque, unfriendly, cold-mannered.' The opposite is 愛想がいい ('friendly, sociable'). Combined with ひどく ('terribly' — adverbial form of ひどい 'awful'), the description carries real sting. The 不- prefix is highly productive in Japanese for negating nouns or na-adjectives: 不便 ('inconvenient'), 不安 ('anxious'), 不思議 ('mysterious'), 不可能 ('impossible').