What Causes A Bitter Taste In The Mouth & Numbness On One Side Of The Body?

Hi doctor, I have been havingbitter and sour taste in my mouth with my throat alwas scratchy and persistent dry itchy cough for last 3 years. Also there is numbness in the tongue and now, lately chin and upper lip and is progressing towards eyes. Also there is numbness in my left arm with lots pain and last 2 fingures are numb.Also tge right foot has two toes big and 2nd are numb and side of the leg and lots pain in the ankle.Left leg has started to get numb.I am seeing a neurologist and have been scheduled for Cranial nerve MRI on July5th.Can U please suggest how to get things diagnosed and to get rid of this hacking cough. Thanks, Zinet