Vent about it. Call your mom, your best friend, your old college roommate that you haven’t spoken to in 3 years- just talk to someone. Tell the whole story, and make it the long version. Explain exactly how you’re feeling and why. If you start to get sick of the sound of your own voice, you’re doing it right. Get it all out of your system and put your feelings into words. Take inventory of everything that is weighing on your heart. But in all seriousness, when you get to the point where you’re sick of talking about it- take the hint. You’ll reach a place where it no longer feels good to talk about it, and the topic just feels stale. That’s when you know it’s time to drop the subject and get back to your day.
Once you’re done venting and releasing those explosive feelings, its important that you actively try to avoid the topic for a bit. You’re only human though, so obviously your mind will wander and you’ll find yourself thinking about it again. What’s important is that you take back control and refocus your mind towards something else.