Help, I am freaking out about the asvab?

I was supposed to take it today and I told my airforce recruiter yesterday that I need another week to study, she told me, I worry too much, but said she wants me to be comfortable when I take it. I took the est and scored in the 80th percentile, but I have no knowledge of mechanics, auto shop, and electronics. I am good with vocab and paragraph comprehension, math is my weakspot, I've been doing some problems, most of it is review for me. I am thinking the worst right now like I am going to freak out and not finish, or get a bad score, this could be test anxiety, and I am just nervous about it. Anyone recently take the test, how did you do? how can i relax my mind and just tell myself I got this? I'm very smart girl, I don't know why I'm not giving myself more credit. I have education, I want to at least get a 72, am I shooting too high?