Talk to Psychiatry on Stoping Antidepressant Side Effects

AoA Hi Sir I was on sertraline 75mg and mirtazapine30mg for a year i get checkup and doctor was saying to stop sertraline and mirtazapine slowly and make a plan to reduce both medicines dosage for a week i had stop taking sertraline and only i am taking mirtazapine 15mg before bed after stoping sertraline i feel low mood angry tired and drowsy sleepy afternoon i feel like headche confussion fast heartrate little bit i am taking multivitamin in morning please suggest me any supplement which can help me to adjust body and brain to normal condition i am facing also weakness in my back muscles and while body and brain please any Help JazakAllah Thankyou