Drawing really helps me relax and take my mind off things I should be worrying about xD
Have you tried adult colouring books? They're so intricate and they take a lot of concentration, so you can relax and forget your troubles

Animal Crossing is like a different reality, especially the nature and beauty of my town! It helps when I'm focused on an activity- for instance, catching fish and bugs to get bells for a PWP, visiting a dream town for inspiration, landscaping.
Make-up helps me take my mind off things, it takes concentration and it's a great way to be creative and expressive.
Try starting a journal- I've been writing journals for 3 years and writing about your problems can help put them into perspective, and it makes it easier to find a solution to them and approach them differently. Or you can write about things that make you happy- writing is really magical c:
Listen to music- find songs that make you happy or perhaps bring back good memories. They can take you to a different world.
Find a good book- you'll be concentrated on it and you'll be in a different world! Books on topics that interest you and make you happy are great ^^
Maybe learn a new language? I find that makes me happy and feel productive, and it takes lots of concentration. You might even want to take up a challenging language such as Chinese or Polish.
Watching YouTube videos makes me happy and occupies me, and sometimes I start with make-up tutorials and end on cat videos, haha.
Exercise and fresh air will make you feel happy and refreshed, especially since exercise releases endorphins, which make you happy

Hopefully this helps you, and good luck! :]