I have to admit that I am not the best at this. People who are goal driven and success oriented tend to take failure and mistakes personally. But here are a few things that I have learned.
Ask for forgiveness from people. Even if you think you have hurt the - ask anyway. I have never had anyone get mad at me for doing this.
Train your brain to think of mistake and failures as stepping stones to better places.
Don't forget - you're not perfect. If you are striving to be something that God didn't intend for you to be - don't try.
How many times have you been hurt by someone elses mistakes. Forgive them. Don't EVER say to yourself, I can't forgive them. Now it isn't about forgiveness, but bitterness, anger and revenge. All of these things you need to get rid of quickly!! They are terrorists on your trip.
Beating yourself up isn't a form of penitence. Growing and becoming more like Jesus is.
Take the time to pray it out! Get alone and talk to God BLUNTLY about how you feel about what has happened. You need to get emotional about this - I mean LET IT OUT! Then allow God to show you things that will bring happiness to your life. They are there, probably right in front of you.
If you have asked Christ to forgive you - then you are forgiven. When you live your life in the shadow of your past failures, God can't lead you into the hope of a new future.