He can’t focus enough to even get dressed most days and take care of himself (using the toilet, brushing his teeth, remembering to eat breakfast)
Google Executive Function and Processing Speed, understanding those will give you a LOT of insight into why your child doesn't seem able to do things that others his age find so easy.
Make him a ticklist or a picture chart of all the individual things he needs to do to complete a certain task, involve him in creating it if he's amenable.
There are loads of free downloadables here www.twinkl.co.uk/
Have a look at Ross Greene's website Lives in the Balance, when ordinary punishment/reward parenting doesn't work, this can really help. www.livesinthebalance.org/
Also see his book The Explosive Child
Does he have any sensory issues? If so, this will help to explain them
www.falkirk.gov.uk/services/social-care/disabilities/docs/young-people/Making%20Sense%20of%20Sensory%20Behaviour.pdf?
How mature is he emotionally? Many children who have AN are as a rough guide emotionally about two thirds of their chronological age.
You have your husband on board and (mostly) school, that is a huge advantage because you can all work together as a team to help your son.
Read up on strategies to help your son's needs, look at ASD, ADD, ADHD, PDA for starters and look for effective and supportive ways to support your son's needs.
Be prepared to find that friends, family and some professionals will all insist he's only badly behaved and you need to be more firm in your parenting. Take absolutely no notice, if they are not medically qualified to state an opinion on your son's traits or diagnoses, theirs doesn't count.
It is a long and time-consuming process to have an assessment, but stick with it and in the meantime, research as much as you can about your sons' traits. Don't focus on 'He may have XYZ condition' because that's for the professionals to decide - he may not have enough traits for a diagnosis - just focus on his traits and what you can do in the form of helpful strategies and interventions.