I use mindfulness, which is using your senses to get your brain focused on the present and off of fears of the future, or regrets from the past. It also is supposed to switch your brain activity from the part that deals with emotions to the logical side.
Distraction works the best for me. I play games on my phone, I listen to audio books while doing housework l. Then I listen to a podcast called Nothing Much Happens Bedtime Stories to Help You Sleep at night. The host writes all the stories about the everyday lives of a bunch of different characters who live in a small village. They are all kind to each other and some have pets with humorous habits. The host is a former yoga instructor who has you do some breathing exercises and then reads the stories in a tone much like a mother reading a bedtime story to their children. I rarely make it past ten minutes of the 30 minute story before I am out like a light. She explains by giving your brain something to focus on it, it helps it relax, rather than racing down multiple tracks.
It's all worked pretty well for me. I still get anxious and angry, but when I start to dwell too much on my fears, and clenching my fists, I make sure I go do something that will give my mind a chance to settle. Not to mention my German Shepherd literally starts slamming into me and pawing me when my I start showing signs of too much emotional overload. He's not a trained therapy dog, but my doctors have said he's likely reacting to the smell of chemicals your body gives off when your anxiety and blood pressure is rising rapidly.