Suggest Remedy For Persistent Dizziness

hi my mam has complained for the past 4 months of a continuous roller coaster ride/dizzy feeling. It is there all the time! She did have a severe cold four months ago - could it be realted to that!!! Her pulse rate was rapid - the doctors controlled this with beta blockers but now she has come off them. The doc says he thinks the heart beat was related to stress of not knowing what the head problem was (she has convinced her self of brain tumours etc). Her blood test for kidney, liver etc have all come back ok. She is booked in for end of july to see an ears, nose and throat specalist. Any ideas??