To put it this way:
I've learned that the mind and the brain are not the same.
The brain makes you function, it makes you move things, move your body and feel pain.
The mind is the powerful thing that has thoughts and makes you feel emotion based on those thoughts. It is the source of your creativity, and the indicator of how you feel when you're daydreaming or thinking about the future or past.
This year, a friend taught me that you can can learn to not let your mind abuse your brain by saying:
"I choose to not worry about this because it already happened, and there's not much I can do about it"
Look around... Do you physically see your problems? Are they sitting next to you? Your problems only really exist when you think of them. You can choose to be present now instead of worrying over your imagination, replaying the past or imagining the future.
If there is a problem outside the now that really needs to be solved, try your best to work on finding a solution.
Where you are now is beautiful, connected. Find the beauty in what you see around you if you don't see it right away.
Take a moment and breathe, you are here, find what feels good and makes you feel happy.