The Waterfalls hitmaker was diagnosed with a potentially-fatal brain tumour, which cost her her sight, hearing, balance and speech, and she admits it's a miracle she's alive at 42.
She says, "I feel like I was spared. I got my sight and my hearing and my speech back... They think it came from cell phone use... I had to do so much research because there was no information out there... I was dancing, touring, I should have been dizzy... but I was fine. I (just) had really bad headaches.
"Two weeks later I was eating French toast and it falls out of my mouth. All of a sudden my sight's gone, my hearing, I can't talk, I can't walk.
"I know I'm here for a higher purpose because my cousin and I had the same disease; he's gone and I'm here. It has to be something I'm supposed to be doing."
Watkins, who also suffers from sickle cell anaemia, will open up further about her health battles in her new reality Tv show Totally T-Boz, which debuts in America on Tuesday night (08Jan13).