Tips on backing on DMV drive test?

I took my second attempt at the DMV driving test today and auto-failed because I messed up really bad on the pulling over and backing portion. It was definitely my fault; I was did fine for the whole test until we got to that portion. I usually can pull over and backing up without problems when practicing my driving, and I even have to pull over to park in front of my house almost everyday. I think I was extremely nervous on the test though and so when I made a small mistake I started panicking and couldn’t correct it within the 3 tries they give us.

What basically happened was: I was told to pull over, and I pulled over a little bit too far from the curb so the examiner told me to go closer (I think my first strike) I pulled over closer and was told to back up in a straight line. For whatever reason, I thought that I wasn’t straight enough yet and adjusted my wheel a bit while reversing. That caused me to back up a little into the “curb” (the curb there was a grassy dirt area rather than the usual sidewalk curb. this might also be why I struggled as I couldn’t tell where the boundary lies) After realizing I’ve made many mistakes already, I could not correct my backing properly within 3 tries and failed.

I know it was definitely my mistake and I’m super bummed out about it. I think this was on account of me not being confident enough during the test and panicking, and I definitely do need more practice on this part. I just wanted to ask if anyone has tips for gaining more confidence in this part? How can you tell (and be sure enough) that you are in a perfect straight line and aligned with the curb correctly? Like what should I be looking for and seeing in my mirrors and windows to know that I am doing it correctly? I know these seem like stupid questions to ask, but I really was never worried about my pulling over and curb parking until now and do not want to mess up on this again. Please also give me any general driving test tips if you can! Anything to help

me avoid autofails in the future. :) Thanks!