Focus on the present.
Returning your focus to the present will help you accept and let go of what you cannot control. It will also help you realize that you can’t change the past, and that the future hasn’t happened yet, so it’s a waste of time to keep thinking about them. (This doesn’t mean that you are unaware of what happened in the past or what is about to happen in the future.) Try taking a deep breath and asking yourself how you are feeling right now.SOURCE