I haven’t read beyond the OP yet, but I wanted to jump in.
My God, your kid could be me 30 + years ago. If it wasn’t music, I didn’t give a f(*#, didn’t put forth the effort, didn’t turn in the assignments, and didn’t care when the Fs poured in.
For me, it was my Grade 12 English teacher who read me the riot act in early June - he made me stay behind after class and said “Your present mark is 48. I can arrange a discretional pass for someone who is doing close to 50 but not quite; in fact, I’m doing that for somebody else. I’m not going to do that for you. You owe me 8 assignments - you need to hand in at least 3 at an 85% or better to get out of here, or I’m making you repeat the grade. You won’t graduate, and you won’t be studying with me, either, because I’m sick of the sight of you.” He then launched into a tirade about how much he hated people who had the brains and couldn’t be bothered. I can’t remember much of the tirade because I felt like I wanted the earth to swallow me whole. I did the assignments, graduated English with a 52% and made it out of high school.
Hard though that day was, I wish someone had done that to me years before - the organizational and study habits you establish early on are really hard to change. I’ve managed, (got a 98 in Introductory Russian when I went back to college to finish my degree in 2004), but it has been a long hard slog.
I hope it has helped Kyle get his shit together - tell him I said it can be done if you think it’ll do any good. Good on you for bringing him along, I say. Sometimes it helps to hear directly what people really think about how you’re doing.