How can i not worry

I tell my brain not to worry, not to fear beauty. I have to do this a few times. As for time, it’s gone and it never existed.
So many things never existed and what a joke that was. Like? how long was my heart not receiving? I thought i can live without it.
Still i keep thinking about it.
Should i let go or not? It's doesn't do me any good when it keep...