go through the roof/ go ballistic
off my nerves
sorry. ans : not at all, don't mention it, that's ok
ever so sorry
how stupid/ careless/ thought less of me
pardon(me)
that's my fault/ it was my fault
please accept our (sincerest) apologies
i must apologize to you for
what do you think of
what do you think about
how do you feel (about)
where do you stand (on)
are you aware of
i am over the moon
i am (dead) chuffed
he couldn't be happier
she's on cloud nine
i am having a whale of a time
she is having the time of her life