I have the same issue. My workaround is to lie in bed, count 1, 2, 3, 4 over and over again (in my mind) and try to focus on these numbers. My mind wanders away all the time but then I just try to get back to counting.
Might sound stupid but I guess after a while of thought-speeding my brain gets bored and calm down. Works for me at least.
That's actually what we do in some schools of zen when we do zazen.
We begin to steady and stabilize the mind by counting the breath. We practice by counting each inhalation and each exhalation, beginning with one and counting up to ten. Inhale — at the end of the inhalation, count one. Exhale — at the end of the exhalation, count two. When you get to ten, come back to one and start all over. The only agreement that you make with yourself in this process is that if your mind begins to wander — if you become aware that what you’re doing is chasing thoughts – you will look at the thought, acknowledge it, and then deliberately and consciously let it go and begin the count again at one.
It eventually stills the mind and will help you, or at least me (the few times I have trouble falling asleep), to wander into zzzzz land.
I does still the mind, but I have a problem that it makes me even more awake. A couple of times I tried that I ended up going back to my laptop and working through the night because I felt like I gained so much energy.
> I does still the mind, but I have a problem that it makes me even more awake.
Then skip the counting and just focus on your breathing (shikantaza). If that also is too much to focus on, do it for 20 minutes or so and then just try to sleep the regular way. Hopefully your brain wont be monkey minding as much as it did before the excercise.
I want to stress that this is not zazen — when doing zazen you should not fall asleep — but a method that I think can be useful also when we try to fall asleep.
Might sound stupid but I guess after a while of thought-speeding my brain gets bored and calm down. Works for me at least.
Also no coffee after 4PM.