Dday, I went through a period where when I started obsessing over H, or being tempted to text or call him, I'd do pushups or cleaning instead. I hate pushups and I hate cleaning. After just a few days I reduced my obsessing substantially and my house and biceps were looking good! It really worked for me, I am that lazy, that my brain just stopped obsessing, it wasn't worth the "work".
I unfriended AND blocked H from FB for a while because it was too painful to look at his postings.