I am experiencing appetite changes (quality: reduced appetite), sleep deprivation, paranoid behavior, feeling anxious (worsened by: psychological stress), mood swings and feeling depressed (quality: feelings of despair). The following also describe me

Thyroid problem? . A likely suspect would be a thyroid problem, probably you should get
TSH & thyroid evaluation.
If there is a family history of mood disorder or depression, a psychiatric evaluation with a trial of antidepressant & low dose anti-
psychotic medication might be indicated.