One of the most interesting cognitive behavioral tricks out there is to - when finding yourself trailing down a particularly dangerous pathway - to envision a stop sign with the purpose of halting the thought. I learned about this one day about 7 years ago when my boyfriend at the time informed me he would be letting his ex visit for a couple of days. The ex he cheated on with me and then continued to live with for two more years. The ex he had broken with like two months before he and I finally got together and started a long-distance relationship, which was still very new.
Naturally, I freaked. What he saw as me trying to control him, I saw as pure disgusting betrayal. The fact that at the same time my father was cheating on my mother with a girl only five years older than me which was wrecking all sorts of emotional havoc in the household did not help. It could not be denied that I did not trust my boyfriend at all, and his refusal to see things my way (although a few months later he would admit that maybe it was wrong in that reluctant placating voice designed to get you back into bed) left me with angry energy that seemed specifically designed to force myself into destructive ruminations that I could not chase away. I spent my time angrily threatening him, running, taking a lot of baths, running some more, then picking up the phone to try to beg him not to do it.
After four days of this, I gave up and tearfully went to see a therapist. "When you have these thoughts," she said, "just think of a stop sign until they go away."
It was only partially successful. The makeup sex two weeks later did a much better job. Unfortunately, that wasn't that relationship's first drama. It continued even far after we had broken up, until recently when I have finally decided to never talk to this person again. It annoys me that someone can need me so much with very little to give.
Point being, the whole drama had more conjured up stop signs than a New Orleans street plan, and it didn't work. I think the issue was having to come up with the actual visual of the stop sign instead of just hearing a voice say "stop!" Still, the concept is useful and should be adapted.
So, I've gone with my own personal favorite: "No!" Not just any "no," but precisely the type of "no" I use on my dog when she is about to do something disastrously wrong, like jump on me when I am wearing a suit. And this also has the advantages of having been practiced and perfected. And to my delight, all day it has been working.
You must understand, my obsessive thoughts about men devolve into two categories. The first is the daydreaming-castle-in-clouds-amazing-sex-not-a-care-in-the-world thoughts, which typically occur when I am very unhappy about what I am doing (for example, like the whole day I spent doing a task I can't seem to finish and hating my job with intervals of concern for my future). The other category can occur no matter how well things are going in the other parts of my life. This is the doubt and overanalytical category. "Why hasn't he called yet?' "Am I being too needy?" "How can I get him to like me more?" "What did he mean by that?" "He was saying no, but his eyes said yes." Besides that last one kind of making me sound like a date rapist, this is the category that really tends to get out of control. Since the last person I kind of crushed on was really hot and cold, he, however unintentionally, really started grinding the obsession sparks in my tiny little head. While I could normally shake it off to some degree, boredom and dissatisfaction also set in, so I got hit with the scenarios in which we would find each other again perfectly happily. Daydream to nightmare and back again.
Today I have employed "no!" an insane amount of times. Still thinking of replying to that text? "No!" Still thinking about that hot birthday evening in his bed? "No!" His song comes on my ipod while running? "No! Next song!" He forwards me an email with a link? "No! Delete without even looking at like and then delete again so that it is gone forever." (Some leeway allowed to forward link to sponsor to prove point that the "no"ing is hard but not impossible.
Can keep doing this until these thoughts stop? "Yes!" Just keep busy and try to stay positive about the negatives - not making them an excuse to bring you down. Honestly, weren't men only adding to that anyway?