I ruined my life and can’t get myself back.

I ruined my life when I got into that online relationship at 15 years old. I told not a single soul about it and he was an older guy (30). It was not a normal relationship either. I did not know anything about how the world works and I was so naive and dumb. No one found out for 5 years. Now i am 20 and dumped him. I can’t build my self esteem back. I don’t know what or who I am anymore. He is completely out of my life, but now who am I?