The Mask coming off is exactly what happens during the Autistic Burnout period, your Autistic traits become more obvious as your brain goes into Safe Mode. You may become more inflexible, your ability to 'mock' making eye contact may disappear completely, your ability to socialise may be drastically reduced or go completely, you may sleep more, want to be on your own more and bury yourself. Life just gets significantly harder and gravity, as i mentioned before, just pulls you down more and more.
--An Autistic Burnout - The Autistic Advocate
