I have larped as a smart student for the past 8ish years

As the title says, I have an exam in a few hours and ive been panicking because I talked to my friend and he said its fucked. For the past 9ish years, really from middle school, I havent properly studied except for 9th grade when I switched schools. Since then Ive never formally studied or attempted to do so. I only study whats on for my tests and skip everything else. I of course didnt know whats good for me and I didnt learn from that mistake. Constant excuses, laziness, procrastination. Whatever you want to call it but I lost the ability to study for a long time now. Ive had something like the sat which ill be taking in a few hours. We have 2 attempts for it. With a period of almost 3 weeks in between. The months leading up to the first try were filled with attempts to study but I was never able to get far. Always start but never able to finish. Same for the period in between these exams. Couldnt focus on what's important and time was wasted. I am a failure of a person and I deserve to be disowned by my family. I am worth nothing. I have been given so many opportunities and ive wasted it. And no matter what I do I just keep going in circles. Try to study ---> words for 2-4 days -----> lose the ability to study for a long time. Ive tried to escape this song and dance so many times, any methods online ive tried them. Shutting down my phone and deleting all the games on my pc? Tried that too. Its not an excuse and will never be one and I frankly dont deserve one. This post is what i think is my last plea of help for even a small sliver of anyone relating or knowing what the issue is. Just dont be like me, I probably wont be entering uni and instead will be stuck at home.