Mazda BT-50: Losing power

My three-year-old Mazda BT-50 suddenly lost power recently when I was driving it, and the powertrain and traction control warning lights came on. I pulled over and turned it off. When I restarted it I heard a whirring noise like metal spinning and immediately turned the ignition off, only for the engine to rev up to full throttle – all while the ignition was off and the keys were in my hand. I kept trying to turn it off when it finally dropped revs and idled out. Have you heard of this happening before?