I think, your predicament is somewhat difficult and iffy.
Yes, you overdone it by giving him the finger, when a simply SORRY
or EXECUSE ME will have suffice.
Now, depending on what sort of person you showed your finger to,
you may and may not get whacked when you meet him again. But if you
do want to make amends, you can apologize if you see him first -
but then again, depending on what sort of person you
offended.
Or you can simply avoid that person forever - just keep your cool
next time.
I know it is difficult sometimes when you are down on your moods,
and always when you are down or moody, something has to happen that
makes it worst. But that's part of life, and the more you can
overcome your SELF, the better a person you shall become.
