This exact thing happened to me in June. I ended up scoring 10 points lower than I'd been PTing, and it was super discouraging. That being said, I would also encourage you to keep your score. Law Schools are going to see a canceled score and assume it was a bad score anyway, so you might as well let them see some improvement! (I kept my terrible score as well)

girl, I'm in the SAME boat! I'd been scoring consistently 160/161/162, and my last two PTS have been 155s, and I'm gonna crash out bc I take my test on Wednesday! Wishing you the best of luck <3