How does this play for you ? I identify as spectrum, what used to be Asperger’s, and have to work really hard to get to visual phantasia, but I can. Also worked hard to remove aural phantasia? via meditation because of negative self talk. Do you see ‘aphant’ as a useful designation? Thoughts, Ideas?
I want the voice in my head to be gone send help.
Look into meditation (extending silence of mind), it won’t work immediately, but it did for me, on the order of years, but worth it, much peace found.
I started with medidating, deep relaxation. Laying flat works best for me. Discovered I can listen to the silence between the words. Then I was able to stretch out that silence until the words were so distant that they were mere reverberation. If there is a movie as well, that can be faded out. Later I learned a more daytime-compatible technique that is a bit hard to explain and could individually differently (opening the crown chakra).
In case it really ets your energy, and if you have access to it, consider talking to a therapist. You might be suffering from sommething like PTSD, depresseion or burn-out (in connection with autism), and those are really disorders that can be treated.
Wish you well!