@beautifuldisasterx0
Hello, I understand what you're going through and how difficult it feels. I've personally been dealing with autistic burnout for the last few years.
It makes sense that this kind of burnout feels beyond burnt out - because the way burnout effects neurodivergent people is different to how it effects neurotypical people.
Often when a neurotypical person gets burnout, they rest and recover. When a neurodivergent person gets burnt-out however, at first they may not realise (potentially due to poor Interoception or Alexithymia) or cannot rest due to having to mask and meet the demands of neurotypical society, or the constant sensory overload or social difficulties etc. This means we keep pushing despite already being burnt out, until it gets to a point so far beyond burnout it is physically impossible to do anything.
Autistic or ADHD shutdown is a pervasive, long-term exhaustion, loss of function, and reduced tolerance to stimulus. It is a state of physical and mental fatigue, heightened stress, and diminished capacity to manage life skills, sensory input, and social interactions, which comes from years of being severely overtaxed by the strain of trying to live up to demands that are out of sync with our needs.
If you haven't already, it could be helpful to research more into ADHD and Autistic burnout. It also might help to look into executive dysfunction, Autistic/ADHD fatigue, and shutdowns (eg autistic shutdown).
Recovery from this can be more complicated for neurodivergent people. Sleep might give you physical rest, but you also need mental rest - giving yourself space where you can fully unmask, engage in your interests, stim, not be overwhelmed by sensory input etc. can help as a starting point.