my girl used to suffer this every term around week 8 onward and in term 4 from week4.
Behaviour would go downhill, meltdowns increase, wanted behaviours that were well established would disappear, fights with school peers would flair up out of nowhere, increased level of negative comments from school, me going insane and booking into the insane asylum.
How is your child coping? Do they need to have some mental health days? It is possible to arrange for the school to get homework sent home for it to be completed at home. The school might not be aware of it but it can certainly be done.
Do what you can to stay sane, do something really special for yourself. You deserve it and keeping yourself sane will help your child.