regretful
regretfully
remorse
self-reproach
compunction
pang of conscience
ochanee
whip the cat
repentance
sorry
my apologies
apology
repine
aiyo
regrettingly
compunctious
guilt
wear sackcloth and ashes
regrettable
bitter
regrettably
regrettableness
sayang
F
ruefully
bad
alack and alas
rue the day
bemoan
could have, would have, should have
regretlessness
deplore
lament
bewail
ruesome
lamentably
guilty conscience
fear
sackcloth and ashes
too bad
miss
regretfulness
afterthink
remorseful
mourning
eat one's words
prick
guilt pang
live to regret
ashamed
disappointedness
shame
self-flagellation
disheartened
penitent
apologize
repentant
pity party
desire
remorsefully
repent
afraid
bad taste in one's mouth
for old times' sake
resentingly
arg
guilt-ridden
blarg
guilt complex
seem like a good idea at the time
repression
commiseration
remorsefulness
regret
cry in one's beer
pathos
regretter
pity
ruth
rueful
self-abasing
roll back the years
sorrowfully
disappointed
regretting
bummer
look back