I’ll throw my two penneth in - write stuff down - pros & cons of different ideas etc - it takes it out your head!
Listening to Tam, I was thinking the same thing.
Perhaps just downloading his thoughts, then pick one and think about what needs to be done to make that one less of an issue. Then move it, and it’s actions to a clean sheet that can be referred to again. Then, at a later date, do the same thing with another issue from the initial download, and so on.
I think this would help with the jumble of thoughts and torment that they create in the mind.
Ian