Called insurance and told "insomnia' was only diagnosis listed. does that mean that is the only one listed in medical record too?

No: In most cases, insurance claim information does not match up with the huge amount of information on a person's medical chart. On the chart, "diagnoses" can include proven diagnoses, probable diagnoses, possible diagnoses, past diagnoses (disorders that have resolved), and many other things. The insurance claim usually needs only 1 or 2 "diagnoses" to get a claim paid. The chart is more accurate.