Panic/anxiety issues, along with palpitations are classic w/d symptoms. Tell your Doc ans ask for help with them.
you need to talk to your dr. it sounds to me like they need to wean you off more slowly. at your age, not being mean, that quick of a taper is too fast. i have worked with elderly women for years, and there are just troo many things that can go wrong with sensitive body systems. the heart included. a more gradual taper should be ok.
Did they wean you at all first, out of curiousity?
Please see your Dr about this.