Dusty,
I agree with the other posts, alittle time getting familiar with the code and you'll be fine to retest and give another go at it.
UT is not so difficult, if you are given time to absorb all the new terms that will be thrown at you when you first get involved. Trig. is needed to help with the math. I was a structural detailer in my former life so working triangles was easy for me. I recommend looking into a school that specializes in NDT. I went to Krautkramer NDT school in Lewistown, PA. they have great instructors that will help you through the learning process. They will have Level I and Level II all in two weeks. I took Level I and then went back a few months later and took Level II, it gave me time to get alittle more familiar with what I had learned and how to apply it, before going on to Level II. If you are a fast learner you may do alright taking both levels back to back.
Good Luck with your retest, and help steer some good young welders our way,
John Wright