Have a routine that you use to start your day that becomes automatic and thoughtless
It's really hard to write a 80,000-word novel, but it's very simple to write down 500 words every morning if it's so embedded into your routine that you don't even have to think about it (and at that rate your novel will be complete in just over five months). You can build similar routines for reading, exercise, meditation, candle-making, or whatever you like. And these routines won't complicate your life because they barely require any effort once they've become automatic.
Selectively avoid tasks that you suspect may be unimportant.
One time there was a huge report that I was dreading completing because it required a ton of work and it was unclear whether anybody would ever want to read it or not. I procrastinated so long that I missed the deadline by three months. Guess what: Nobody even knew it was gone (our group's interests had moved on to other topics), and had I actually spent 50 hours writing it, the effort would have been totally wasted. Pausing to consider whether work is truly important or not can yield a lot of time savings. This doesn't work for everything (obviously most of your job responsibilities are necessary/required) but can periodically be a valuable tactic. This will also teach you to think more critically about time pressure, and learn when to discount it (and therefore be less anxious day-to-day).
Reduce the number of ways people can reach you.
After you've checked SMS, WhatsApp, voicemail, e-mail, your second e-mail account, Facebook messages, LinkedIn messages, Twitter mentions, Twitter DMs, Quora messages, snail mail, and Slack for the third time in a given day, you've lost the opportunity to actually, ya know, get anything done. Narrow down the number of communications media you use, and batch process the messages that arrive, to reclaim your day.
Get comfortable not having an opinion on most things.
At least 99% of the time, our opinion of a certain topic is totally meaningless and has no impact on the real world, yet we spend countless hours hang-wringing over crap that is totally out of our control. Newsflash: Your rooting interest in a football game has no influence on the outcome of the match. Newsflash: Your opinion on gay marriage will not change how the Supreme Court rules on the topic. We would all save a lot of time and aggravation if we confined our opinions to domains over which we actually have control. (Which isn't to say that there's no value in being an informed citizen, but man we sure do spend a lot more time advocating for our own opinions than working to change the outcomes.)
Remember that in 200 years, it's very likely that nobody alive will know that you ever existed.
Most of our daily frustrations and triumphs will amount to nothing in the end. So: Don't spend your whole life doing things that make you feel crappy. Very soon we'll all be dead and none of this will matter. There's nothing simpler than that.