I start highschool soon and my life feels like it's already over

I don't know how to format this so I'm sorry if this is clunky, I really just need to say this somewhere.

I've been failing school since 5th grade, I completely skipped 6th, I did 7 and 8 online but I didn't learn anything and I just barely got through. I feel like such a failure. I honestly want to go to school and I want to learn and be smart but I have no energy for it, I also don't think I'd be able to catch up considering I don't remember a single thing from middle school. I feel like such a joke because I'm always making excuses about how I'm "not mentally well enough" even though I have the energy to play video games all day. I am pathetic.

I don't know anything, I have no hobbies, I don't go outside, I'm unhealthy, and I don't know what I want to do with my life. Everyday I feel miserable and I'm constantly thinking about cutting myself. I've gone to therapy for the last few years and I felt like it didn't really help. My mom has been making more money so we don't have the insurance for it anymore, so even if I wanted to I'd just feel like a burden for asking to go because I know it's stupidly expensive.

I don't know what to do. I feel like it's too late for me to start over and my only way out is to end my life.