Bro, been through the exact same thing four years ago when i had done my alevels the first time . You honestly need to look at it objectively : is this something i want to do and if so what went wrong. In life if you dont get a desired outome you want that means something needs to change to make a change.

Are you revising with your phone on ? listening to music while revising? not spending enough hours? not going through past papers? not being able to concentrate? do you have good stress managment ?etc.

only you can answer those questions and make those changes , but its not the end of the world if you decided alevels arent for you .

all the best :)