Collocations for bitter - adj.

be, feel, seem | become, grow, turn
He had grown bitter as the years passed. | Loving relationships can turn bitter.

remain | leave sb, make sb
The divorce had left her bitter.

extremely, very | quite, rather, slightly

about
She still seems quite bitter about it.

towards
I felt very bitter towards them.

be | become, turn
The weather turned bitter.

remain

extremely, really, very | quite, rather

be, taste
The drink tasted bitter.

extremely, very | rather, slightly, somewhat