Heroes aren't perfect. In today's society, the media is constantly digging up the skeletons in the closet of those we admire most, but this does not make them any less of a hero. Look at the book of Judges filled with twelve heroes who freed Israel from its oppressors.
But these twelve were far from perfect, among them was an assassin (Judges 3:20-24) and a sexually promiscuous man (Judges 16:1-2).
Even with these faults, they (eventually) obeyed God and were used by Him to accomplish great things.
If you think you have strayed too far away from God to ever be used by Him, think again. God's door is always open and His mission for your life doesn't expire till your last breath. You can be a hero, even with your shortcomings. Sometimes it is our faults that finally point us in the right direction, to obey and trust God's plan, and be the hero He has called us to be.