A phobia goes beyond ordinary discomfort. Whether it involves a specific object, situation, or environment, the fear is intense and often seems to have a logic of its own, even when another part of you recognizes the reaction is out of proportion. Avoidance tends to keep the phobia going, because it prevents you from ever gathering evidence that the thing you fear is actually manageable.
Therapy works by helping you understand the fear and then gradually changing your relationship to it. That usually involves looking at the thoughts that drive the anxiety and where they came from, then building up exposure in a careful, incremental way so you can face what you have been avoiding without being overwhelmed. Many people are surprised by how much ground they can cover once they have the right support and a clear plan.