I skipped on a girls bat mitzvah because she liked me
Why didn't you just tell her that you didn't like her also?
The girl was really great and I couldn't do that to her
You were definitely in a hard situation, but you shouldn't have skipped her party if you had already said that you would attend. Next time, make sure you are actually willing to attend an event before accepting the invitation.
I just didn't want the confrontation.
That still doesn't excuse you of skipping. Next time, honor your commitments.