What's a good first step for defeating anxiety?

First of all, i'm not quite sure how to phrase this, so bear with me.

I feel like I have a vast amount of untapped potential, but something is preventing me from realizing it. I am aware how broad and somewhat naive this sounds, but it has become an extremely frustrating issue in my life and it weighs down on me nearly every second of every day. I would not describe myself as a clinically depressed person, but I am extremely "in my own head," and my anxiety tends to get the better of me, stopping me before I begin, if you will. I feel like I am ready to break free of this affliction but I am not quite sure where to begin, so i'm turning to you Reddit!

I am open to any suggestions and am willing to give thought to just about anything. Thanks!