There's also things like this - I like Tibetan Singing Bowls, they tend to have a calming effect.
My boyfriend plays that stuff a lot. I was very sceptical to begin with, but now I find it very relaxing. The cats love it too.
So I put myself on a data diet, which payed off immediately. Just a couple of moments to stay up to date and sometimes some wider view on the whole thing are enough for me.
I did this too. It's annoying that even good newspapers resort to tactics designed to cut you deep at an emotional level. It's as if everything is in caps lock when I read the news. I stopped reading news on Twitter because there it's like it's in caps lock and font size 72. I just can't take it.
Another thing that I found helpful was a communication diet. Some days I don't open forums/chat servers/places where I can comment at all and instead spend my time in solitude. Online I no longer argue with discourteous people and just block them. It has made me a lot calmer and happier.
Yoga and bike rides have made me much happier too. I always shied away from yoga as a thing for new-agish hipster moms but I was wrong. Another thing that helps is going to bed a couple hours before sleep, screens-off, and just reading lots. That said, I am kind of priviledged. I can do lots of reading and take a walk in the afternoon because I don't need to be at work.
Leonard Cohen (Bird on a Wire): I have tried in my own way to be free
Mrs Hudson (BBC Sherlock): Sherlock! The mess you've made!