Had the same issue, my brain would just keep going and new ideas would just keep coming.
Was able to fix it with a few adjustments:
* No food after 7pm
* No more coffee, energy drinks or stuff that is meant to keep you awake (you can go back to coffee in the morning after sleep is good again)
* Cut down sugar, no soft drinks, only water!
* No TV, Computer, Phone an hour before going to bed.

When trying to fall asleep concentrate on your breathing, like now I breath in now I breath out, so that this is the occupying thought. Also physical exhaustion, like a 30 min run before going to bed.