Could you tell me what the meaning of shredding my thoughts is in the following context?
The complete phrase is
I had only a few seconds to wonder why before the needles returned, shredding my thoughts
It's included in this text:
I AWOKE WITH NEEDLES in my brain. Thousands of them, biting, blocking out everything. Then they disappeared for one dizzying moment and I got my bearings. It was morning, early; amber sunlight poured in through my bedroom window. I was standing but not on my own strength. Two hands were gripping my throat, and they’d been shaking me. The needles, that was my brain crashing into my skull. I had only a few seconds to wonder why before the needles returned, shredding my thoughts. My eyes were open but I saw only white flashes. A few sounds made it through to me. “SLUT!” “WHORE!” Then another sound. Mother. She was crying. “Stop! You’re killing her! Stop!”
Educated by Tara Westover