There’s nothing for you in the past. It’s worth repeating that to yourself once in a while. There’s nothing for you in the past.
Many of us spend way too much of our time thinking about things that happened in the past. How we could have done this or that. Maybe if we made this decision, or chose that job, or that friend. Or maybe we reminisce on the good old times. Ruminate on what it would be like to bring something back, or to revisit something again.
It can become self destructive and can hinder both your direction in life and your mental health. Stop living in the past and live in the present. The past is a lonely place full of memories where nothing can be changed. Move on with your life, focus on the present and the future.