bitterly (
http://definr.com/bitterly)
adv 1: in a resentful manner; "she complained bitterly" [syn: {with
bitterness}]
2: indicating something hard to accept; "he was bitterly
disappointed"
3: extremely and sharply; "it was bitterly cold"; "bitter cold"
[syn:
piercingly,
bitingly,
bitter]