There is no mistake in your life that God cannot use. He works everything into the beauty that you become. So stop being weary of the minuses that were your past. He can use anything and everything. He can make the meanest heart into the meekest heart. The proud, he knows how to humble. He alone has the ability to use the flaws and turn them into a style that eventually become the UNIQUENESS that is YOU!
Sometimes the heart of man can truelly be deceiving. Making us see only the impossiblities of our souls and thinking that when we loose, all is lost and the pains will never go away. But only God knows that everything about you can be a wood that will stoke the embers for the finished product.
It might be difficult sometimes to believe but if you can go through your memory lane over and over again; you will find that there were things in your past that you could never attribute for good that now in your life you can see was neccessary for good to happen. You will see that your heart breaks were neccessary for you to meet better people and get better. You will see that that high school sweetheart had to give way to your present hearthrob who understands and loves you better. And maybe you are still on your way, but you have become a nicer person because of your experience.
If you look at your failures you will see that in every of them is a lesson that you can not do without in your life right now. Yes, it's a phenomenom that our expectation-filled hearts detests to fathom. But alas! there lies the true spring board of our life's charts.
Stop regretting your mistakes and start appreciating them!