When I am stressed about something I tend to wake up far too early and struggle to get back to sleep, even if I'm not actively thinking about whatever is stressing me, it's like my general subconscious levels of stress are the problem. I wasn't very functional on little sleep even before my injury.

Things which reduce my stress also seem to help my sleep. A Mindfulness course I have been on has been the most help in that respect.

I also no longer drink any liquid after 8pm. That way when I wake up hopefully I can drift off again without needing to wake up properly to use the toilet, after which all is generally lost!