There is no turning back at certain points of life, other than to remember the past as opposed to living the past.
Behavioral Scientist Dr. Steve Maraboli has studied life and talks about the difficulties that are presented to each of us, "Life doesn’t get easier or more forgiving, we get stronger and more resilient."
The author also wrote in his book "Life, the Truth, and Being Free," “Sometimes life knocks you on your ass... get up, get up, get up!!! Happiness is not the absence of problems, it's the ability to deal with them.”
Today, don't look back with regret and what-if's, but instead look forward with what you learned from the past.