I just can't get past it.

Today at work I was doing fine and then like a strike of lightning I felt physically ill from the thought of something long ago. I had to stop what I was doing and regain my composure. I just can't stop. I can't get past any of it. Someone told me happiness is a choice, I think that's too watered down, I don't know how to be happy or focus on anything unless I can get a time machine, that is the only way I know how to cope and stop posting on here about trauma and having to stop working in the middle of my shift.

Here's the catch though, I don't have a time machine so I'm fucked and idk what to do besides let out the sadness.