This is Dr. David
you could be suffering from fear of open spaces or agoraphobia.
excessive anxiety can cause panic symptoms and dizziness and feeling unstable.
are you on medications to help decrease anxiety?
No - only meds I am on = Levothyroxine
you should talk to your doctor about medications which can help decrease anxiety and panic symptoms.
you might benefit from seeing a psychotherapist to do talk therapy as well.
there are medications like SSRI agents like sertraline which can help.