Okay, so that answers that.
I hope you can find a way to let go of beating yourself up for choices you made in the past. All the pummeling in the world isn't going to change them! They were the right decision for you at the time, with the information you had. That's the best any of us can ever ask for.
You mentioned potentially going back to school...maybe it would help reduce your anxiety if you were to take a little pressure off of this test. This test is a stepping stone. It's not the end-all, be-all; it's a tool that will help you have the financial independence and freedom that will allow you to ask yourself, and not just theoretically, "What do I want to study now that I can afford to go back to school?"