Try engaging in a good workout session and then take a nice cold shower (not freezing cold but avoid hot water). It will give the brain a break and will help release tension, although, as you all already know this problem tricks us in so many ways that we need to re-adapt ourselfs constantly. The ultimate goal I guess is to really get rid of this inner sensation of needing PMO that wasn't there in the first place. Stay strong and play smart bud.