Just wondering why you would say that you disappoint everyone?
Is this something realistic? Are you really disappointing people, or is there
something else going on? Some environments are hostile, for reasons that
I don't understand - so is this maybe what you've been caught up in?
Try to go in with confidence, that you are prepared to do a good job, that
you will offer to help others when you can, and don't let anybody walk all
over you. I mean - always be on time for work, be organized, accurate,
reliable.
All the best with your job.