Autumn I have read a bit more, not all the posts from earlier, but enough to understand that you have a lot to go through and are going through a lot, as is paul and aloneagainor ... and some others here.
I have been through head injury with someone very stubborn. I tried lots of things to help, as did a lot of people around him. I think that the hardest thing was that he did not really understand that everyone was putting out for him, he did not appreciate the effort, concern, love and kindness. In that, he did not put out as much as everyone else and that was the problem. He also had it in his head that being deaf was second rate citizen stuff and he didn't like himself. He was thirty when the head injury occured.
There was brain damage that was eventually diagnosed ... damage in the frontal lobe ... he could not put in place a solution to a problem although he knew it existed ... entirely frustrating for him. But with knowledge of the problem and patience he was able to relearn and create new neural pathways. It just never stuck because he was continually polluting himself with substances and the thoughts in his head were negative. I spent every day doing "counselling" with him, tried to help by doing things, tried to help by giving him the things to do, tried to help by smiling, encouraging, learning sign language, the works.
The one thing that I didn't do was quit drinking ... I have always wondered if that would have made a difference. My husband died a couple of years ago ... from a kidney disease, he also had this, just to complicate things. The last time I saw him I told him there was nothing wrong with him, he just needed to stop all the smoking pot, cigarettes, coffee and start to listen to the wonderful advice of everyone around him. He just couldn't do it.
I suffered a lot with Peter, all his insecurities became mine without me realising it, he hammered me because of his low self esteem and outlook.
The advice I have for you Autumn is to be yourself, to love yourself and look after you. That way maybe he will see the difference and it will permeate his thinking and he will pick up (slowly) the things that are obviously working. To encourage all the good things that he does achieve, like the cheque writing and to ignore the crap, do not react to it ... the talk of death etc., try very hard to walk away from that and not give any fuel to it. Do not react, people respond to things they get attention for ... it reinforces the thinking somehow, even if it is non agreement.
I also think that to take the emotion out of it all can be a good thing, to not attach any feelings to all the reasons behind things can make them easier to understand and process. We can react first to emotion, second to the words and intended message. Sometimes we don't get past the emotion.
Wishing you lots of strength at this time, I know just how difficult, challenging and confusing it all is!! To you too Paul and aloneagainor!!
lots of love and peace
Brigid