Hello dear and welcome to the medhelp forum. I can understand your concern. If you have ruled out cardiac causes and a CT, EEG have been done without any significant findings, you need to consult a neurologist. This may be a cervical spine degenerative disc disease or prolapsed disc causing nerve compression and these symptoms. Migraines need to be ruled out along with nerve entrapment on the shoulder and axilla. Try to take it easy and with a relaxed mind. Wish you all the best.