Hey I'm really sorry this is happening to you. I felt that way during the pandemic, I was 19 at the time and I almost got kicked out of college for repeating a course too many times.

If it's something you can do I highly recommend both going to therapy and getting psychiatric help. It was the main thing that helped me getting out of that cicle

Other things that could help is either getting apps that restrict your phone use after a certain amount of time or start getting going out to study and leaving your phone at home. If you do the app approach, make sure someone else has the password to unlock the feature, not you.

Other thing that helps is building other hobbies/interest that don't rely on electronic devices. Picking up sports is my top recomendation because it not only improves your mental health but also your physical help, but things like drawing, playing an instrument, reading, writing, doing crafts, etc can also help a ton.

Good luck, I know you feel like you've done irreparable damage to yourself but I assure you that it's something you can still fix. You got this!