My mind is very prone to overthinking and I have to work hard at distraction.
Sometimes reading or watching television is not enough. My mind can wander and I'm back to worry, anxiety and dread.
My most effective distraction activities are 1. Not alone and 2. Are outside of the house and 3. Are physical as well as mental.
I volunteer at a food bank once a week and this is often my “free-est†time. I think it is also down to the fact that many of our clients (obviously) have very real issues, compared to my “imagined†ones.
But to answer your question, things like hard sewing or embroidery or delicate craft are really good for concentrating.
Dancing hard in the kitchen to very loud music from your youth can be a good quick fix.
Cleaning - don't laugh - yes, cleaning. My sinks are shiny and bleached and my toilets are extremely white. The productiveness of cleaning and doing jobs can (no joke) improve greatly how you feel.
I find it is best to keep away from the ‘phone and the computer. I'm always reading horror stories on the Daily Mail website and they add nothing to my life apart from more potential worries.
Can you do cryptic crosswords? If not, learn how to. I don't do them every day but I do at the weekends and it can sometimes take a whole day on and off to crack.
Finally, even when working from home, pop outside and raise your head up and look up at the sky for a few minutes constantly. The combination of being outside and looking up is very powerful.
Just read these suggestions. Think I won't be starting to write self help guides for a living. Not sure any doctor would recommend kitchen dancing to Duran Duran.