Spending your time imagining what would have been if you could have changed some little thing, some little decision in your life, is counterproductive. Think about how you can improve for the future, today, but don’t waste your present time thinking about how you could have changed the past.
We could all trace our current position to every decision we have ever made. For example, where you sat in nursery school influenced who your friends were, which influenced what your interests were, which influenced how well you did in first grade, and so forth. You could ponder these things endlessly, but it wouldn’t get you anywhere. Take a wrong turn on your way somewhere and it won’t pay to pull over and question why or how you took the wrong turn. What you need to do is think about how you can get from where you are to where you want to be. This same logic applies to depression: Don’t wallow in how much better everyone else’s life is. Think about what you need to do to get where you want to be.
Research on athletes who came close to winning but lost in the Olympic finals found that those who spent the least amount of time thinking about how things might have ended differently were the most satisfied with their experience. Try to apply this example to your own life. Stop spending your time thinking about how your life might be different if you had done things differently, and instead focus on improving for the future.