For Tension And Anxiety Doctor Prescribed Me Zapiz 0.25 Mg

For tension and anxiety doctor prescribed me Zapiz 0.25 mg or 0.5mg tabs a day that i have been taking for last 4 years. now the evening i stop taking it before going to bed i have horror dream and get panicky and pulsation of heart and finally unsound sleep. is it zapiz withdrawal syndrome? if yes, how to prevent it and cure it?plz suggest.