I was the same way as you. Not someone who would study, do homework. I would do projects, usually at the last minute though...

Anyways, half way through grade 11 and my god, homework and studying are SUPER important. Really. If your mental disorder(s), ADHD, whatever affects you in school, you can try for an IEP or 504 plan, wherever you are. Try doing what people here suggest (a lot of the above post are good, so I won't repeat them), but if you can't manage even listening to these suggestions and going through with it, then try for one. Without it now, I would be failing all my courses. Honestly. Hope you find something that works for you .