I tried meditation at one point. In part, I probably have always used my (creative) job as a meditative tool. Not with everything but some monotonous tasks tend to send me into a kind of 'flow' state where the time just evaporates. I might be having random thoughts pop in but, it's not as intense. Having stuff playing in the background also helps me to dissociate.
If I'm worried about a particular thing though, it's incredibly hard to get my mind to drop it. That's the worst at night when I need to sleep.
Certain things I suppose you can try to do: Do all that you can to do to try to fix the issue. Compose that email, buy what you need for the upcoming project, look into practical ways of solving it. After that though- tell yourself, there's nothing more you can do in the present moment and, worrying about it will just make the situation worse. Not saying that will work but, you can try I guess.
During my most intense stages of limerence, I used to walk miles and miles listening to music. To basically just bombard my body with sensory stuff and come back too tired to think that intensely.
Another thing would be to do something genuinely potentially dangerous if you don't give it your full attention. I sometimes find that I feel like I've been worrying less when I use power tools because I'm concentrating so hard on not cutting my fingers off! I imagine sports like rock climbing require people to give their full attention to what they're doing. So, while it's not a quick fix, it might be a way of sometimes putting your focus somewhere else.