This sounds like severe autistic distress and burnout, not behaviour or bad parenting. A 14-year-old autistic child screaming for hours, waking repeatedly overnight, refusing to leave the house and becoming unsafe in public is a sign her nervous system is completely overwhelmed.
Illness often tips autistic children into crisis, and once they’re in meltdown there is no reasoning or logic that will work. This isn’t about boundaries or giving in – it’s about a child who is no longer coping.
OP, you are not failing and you are not weak for finding this unmanageable. Anyone would be at breaking point dealing with this alone while also trying to protect other children. Going into low-demand mode, cancelling plans and focusing purely on safety is the right thing to do right now.
This is at crisis level and you need urgent professional support. Please contact your GP and ask for urgent help via CAMHS / paediatrics, especially around anxiety, sleep and safety. If she is already known to services, tell them clearly that you cannot keep her safe when she’s like this.
Asking for help does not mean you don’t love your child or aren’t trying - it means the situation is bigger than one parent. The system should be supporting you here.