Hi Kimmi
I find the biggest thing is not stressing about not sleeping - all part of the journey I guess. Prior to my diagnosis I was an excellent sleeper! But now have issues usually leading up to next treatment.
Have you tried writing down all the things going through your mind? I do this if things start to get out of hand - somehow committing all those thoughts to paper take them out of my mind - a bit like wiping a blackboard clean at the end of a lesson. I keep a notebook and pen by the bed for this purpose.... Then I will focus on my breathing to relax my body and usually drop off then! Otherwise agree with @Afraser - a cup of warm milk can help too.
Take care