I am sorry to hear about your medical problems. Half a body numbness that comes and goes can be due to a mini stroke or transient ischemic attack, compression of spinal nerves, Vit B12 deficiency, vitamin D deficiency, anemia, vaso-vagal attack, multiple sclerosis, hypothyroidism, diabetes and panic attack. It can also be a type of seizure.
Since a confirmed diagnosis cannot be given on net please consult your doctor regarding this as soon as you can. Hope this helps. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.