I cant give you proper advice, but I can sure give you my opinion.
This is how my anxiety started out. I was such a happy camper, until BAM, this creepy feeling hits me and I just feel like Im not really "there" and Im going to die, and I wont make it, and I am telling you, I went to EVERY DOCTOR I have done EVERY TEST. and all I got was "Anxiety" but then when I looked further and further into it, they told me, this was called a panic attack. Which is such a feeling that hits your out of the blue. Nothing really triggered it, everything just came out of the blue, and they started to come closer together, and I was always worried after the feeling happened, until i got sooo into it, I started to dwell before it happened.
If I were you, I would go see a psychiatrist, and a doctor.. whatever makes you feel better... make and app for an MRI or CAT scan, it might get your mind at ease.
I have had these symptoms for many many years, and to me it sounds like panic attacks... I know its hard to take, but I hope I helped a little bit..