L2L,
I know it's hard.
Lately I've been able to catch myself about 5-10 minutes into my obsession about my son (what is he doing, why is he doing it, what's the logic in it, where is it going to lead him, how will I be involved, etc.) and have been able to STOP and say a prayer to my HP to let it go. It doesn't always make me feel wonderful, but it does help me to take the focus off of my son - I have no business obsessing about him because he is gonna do what he is gonna do regardless of what I say, do, think.
Say a prayer to "Let Go and Let God" then focus on something else.