It is normal to be anxious about things sometimes. I also didn’t have my GED and had dental issues and felt less than because of it. The dread I’d feel having to go through the testing or the cost of fixing my teeth made me not want to go through either. I did eventually do both, after basically giving myself an ultimatum. I was depressed and didn’t feel like existing as well, but there were a few people that I really didn’t want to let down. The place by me that let me obtain my GED has a process where they would test your knowledge, then tutor you on your gaps, then let you take the tests. I ended up passing with pretty high scores because I over prepared, which felt really nice. That gave me enough confidence to get my teeth fixed and worry about the cost later, which also boosted my confidence. The anxiety didn’t go away entirely, but I remember the feeling of overcoming what I thought were impossible tasks. That was over a decade ago. I’ve since gotten a good career and I’m currently the most confident I’ve been. I don’t know if my story will help you, but maybe you knowing you aren’t alone in that feeling can offer some solace. My only advice would be to not let the anxiety control you. It’s not a switch you can just turn off, but maybe by tricking your brain by remembering failing won’t hurt/kill you, you can overcome yours.