Let go of what you've failed to do!  The saddest words of the tongue or thoughts of the heart are; "if only I had done that".  Not one of us escapes the constant reminder and pain of opportunities missed, a responsibility unfulfilled, a decision sidestepped, words of love and gratitude unspoken, a child or spouse neglected, a chance missed.
 
We feel we've failed because of what we didn't do.  We could have gone to college, we could have married that person, we could have taken that job, we could have helped that person, we could have said "I love you" more to that dearly departed loved one...the list can go on and on and on.
 
What you must do today is forgive yourself and let it go.  The same cross that forgives your sins of commission also forgives your sins of omission.  Renew your faith in the God of second chances.  He can "make up to you for the years the locust has eaten" (Joel 2:25).  Ask Him for a new dream, then forgetting those things which are behind, reach forward to those things which are ahead (Phil 3:13).