I am so sorry to hear about your husban's plight, Juliam.
My husband suffered dreadful problems because of the DAs he was oversubscribed.
Eventually we were offered counselling with a neuropsychologist who dealt with psychological problems caused by neurological illnesses and/or their treatment.
We both received counselling for 2 years which helped us both come to terms with our situation and cope with it.
All this was on the NHS and we had to be referred by a consultant.
Could you find out if this is available in your area?
You really need a person who knows about the conditions and is trained in appropriate methods of support.
If you go to a private counsellor they can be Internet-trained or just enthusiastic amateurs!
We are in Leeds but I assume all Health Trusts have a neuropsychologist in their area and your husband should qualify for help.