Hello! After a carefully assessing your problem, I would like to suggest you some simple advice-
1) Being postmenopausal & living lonely & a predominantly sedentary lifestyle, particularly 'seating job' causes a neck muscle spasm.
2) It is this neck muscle spasm which is responsible for your symptoms of imbalance / unsteadiness.
3) The is a common clinical condition in your age group, popularity known as VBI- Vertebrobasilar insufficiency
4) This is very much curable with simple management with cinnarizine
, after consultation with your physician or an orthopedic surgeon & you are required to have regular neck exercises & physiotherapy
Thanks & wishing you an early recovery!