I have been on Lexapro 20 mg for about 2 years on and off. But once i try to wing myself off it i get extremely emotional and am constantly lighthead and nauseous. I could never take it so I got back on. And I have gained almost 80 pounds since i started taking it!! Its taking over my life and the price keeps going up for it so I went to my doctor and he put me on generic Prozac(Fluoxetine) 20 MG. I have been taking it for two days and am starting to feel withdrawl symptoms from the lexapro. has anyone taken the generic prozac and gained weight and does anyone know if the symptoms will go away? :(