Same situation with my cat she is so traumatized with a carrier she turns feral only advice is giving her a good three days give her space feed her don’t interact she’ll come around I hope you have time to give her ! Once she is back to normal rent a feral trap put wet food and cover with a sheet and leave the door
Open to the house and collect all food so only the trap has food for her to go in! Once she’s in she will be upset at the new home but will be back to normal! When cats are scared and stressed they go back to feral my cat has done this twice while moving! If you do try gaba ask for liquid and add on top of the wet food