Just remember that, at the time, you did what you felt was right.  Much (too much to relate here) played into that decision and you made a choice.  In the end it did not play out as you might have hoped but that is not really the point.  Best case, next time you have this experience to refer to before you make the next choice.  Don't want to preach, but you did a good thing, you also got a bit of an education to help you through life, just don't let one bad apple sour your heart.  Toss that stinker out and start over.