One of the reasons I chose to study psychological sciences at the undergraduate level was my almost paralyzing social anxiety. I would not talk to peers, they'd assume I was a hostile person and I would get socially isolated.
It was a vicious loop - I'd go in a situation, deathly scared of being judged, and naturally be defensive in my interactions (no eye-contact, no smile, appearing uninterested or rude) and would get responses aligned with my behavior and my premonitions about the situation. Everybody would assume I was hostile and treat me accordingly - the self-fulfilling prophecy in action.
The self-fulfilling prophecy is such greatly involved in cases of anxiety that in therapy, the first step is usually to identify the anxiety loops clients have built.
Almost always we identify one or many loops that perpetuate the distress. Here are some very common ones:
The Loop of Health Anxiety:
The Loop of Sleep Anxiety:
The Loop of Anxiety about Fainting:
Breaking the loop is possible when you start becoming aware of the process in action. The loop can be broken anywhere along the arrows with easy techniques that you learn in therapy.