You will have to learn to live with your mistakes, everybody makes mistakes and its all part of a learning curve in life..
The Reality is, you cannot go back in time...Everybody has wished at some point in their life to go back in time..
You will have no doubt, seen hundreds of postings especially on You Tube, that "explain" how to travel backwards in time...All i can say is use your own judgements for what is truth or nonsense...
Almost all of us on Paranormalis do believe that time-travel is possible and many have conducted experiments, but at this moment in time we are all still in the experimental stages, including myself...There is no simple way of travelling through time and it will have many many dangers that few people are aware of..