A lot of good suggestions here.

When I can't sleep when I have a lot on my mind, I too, like Karen said, write everything down that I am afraid I will forget to do. It helps a lot.

A couple Tylanol PM's work too and some Chamomile tea, even if you drink it with dinner. It will relax you.

A warm bath or shower helps.

A cool room (temperature wise) helps. People sleep better when it's cool.

Sometimes reading a few pages of a book before bed gets me thinking about the book so it's easier to fall asleep.

Last thing, for your sore neck and shoulders, try a thermacare wrap overnight. It helps me a lot when I have sore shoulders.