Self doubt and having moments of feeling like an imposter happen to everyone -- and I mean everyone! Think of the most accomplished and successful person you know. Yep, they've felt that way too. It's human nature.
I did some reevaluating of my life and realized that the reason I was failing at everything I touched was because it wasn't in my destiny to do them. So I made the decision to live my life according to what was going to make ME the happiest.