Many of us have tough times, and sometimes we may feel as if we're a mistake.
But God doesn't make mistakes. The Bible says in Psalm 139:14 "I praise you, for I am fearfully and wonderfully made". Some say that in this verse, David, the psalmist, expresses his belief that God created each person individually and intricately, and that God's creation of humans is distinct and marvelous. David also believed that God's creation of humans is different from the creation of everything else, and that no two people are completely identical.
You and I have some very specific gifts that God created in us, find them. Use them. And glorify His Holy name!