how do i stop obsessing?

Find a comfort object/person or an anchor. You've already made the first step by acknowledging the problem! What you need to do now is to try to stop thinking of it in short breaks until it gradually becomes a longer period of time where you don't think about it. It might take time and you'll definitely have to put in a lot of work, but if you truly want to stop you'll find the strength!I wish you the best of luck. <3

Just try and distract yourself with something you enjoy.

Try finding things that distract you. Sometimes just tv or a good conversation works. If not, sometimes any really intense sensations can help snap you out of it. Try putting an icepack over you're face and breathing into it, or go for a quick sprint outside (or even find a place where no one's watching you and run in place or do jumping jacks for a minute if that's the best you can do in the circumstances). If you try a few different things like this you should find one or more that work for you, and then you'll have them for future reference when you need them most.