I don't know how

Give yourself a few minutes during the day to think about what is bothering you.
Then look at the different ways to fix it.
Choose the best option, just do it. Then move on from it. You did your best. Then its time to move forward and discover new exciting things to occupy your mind, to give you peace and happiness again. Let whatever it was go. Time to heal and move on...

Walk. A long one. Just walk

Iam sorry you’re feeling this was sometimes it’s really hard to find peace. I try to distract myself with small things or talk to someone I trust.

Time. Nothing else works for me. Also changing your environment, seeing something new and keeping yourself busy. Filling your mind with other things and pushing those you don't want there away.