Hello Da******* Antidepressants medication are mainly used to replenish the decreased amount of Monoamine Neurotransmitters in brain. A lot of research found that depressive disorders are due to decreased monoamines specifically Serotonin and Norepinephrin in specific brain areas. Psychiatrists commonly prescribe the antidepressant drugs to fill the deficient areas of neurotransmitters. So if you were taking medication for long time and stopped suddenly it probably resulted in withdrawal syndrome (serotonin withdrawal) in which on may manifest as dizziness, headache, vertigo, parenthetic sensation over head and extremities, nausea, vomiting, diarrhea, flu like syndrome, insomnia, tiredness. so best way to avoid such symptoms is to taper antidepressant medication gradually over 1-4 weeks, for anxiety and insomnia you can use Clonazepam in small doses thanks.