No, it's not your fault. We all make mistakes, ok? We always have reasons that lead to them, and we rarely make them with bad intentions in mind. At some point we thought something was the right thing to do, but we learn to understand that it wasn't... that's growing, and that's positive. Don't let that ruin your life, forgive yourself, which will only make you stronger. If you wish to talk, I'm a PM away. Sending hugs.