I dropped out of high school when I faced a slump like that. 10 years later, I'm still stymied by my lack of diploma. I've found ways around it, and I still get hired. However, from my experience, you must finish high school. I also had problems in grade 10, puberty combined with drugs and a general discontent at what I saw on the news led to a "tune in, turn on, drop out". I don't recommend this path. You have a long life ahead of you and the improvements you make in your life now will be worth much more years down the road.

There are a few things I do these days to increase my will-power. Working out at gym does wonders for my endorphins and dopamine, the neuro transmitters that get shit done. reddit.com/r/fitness has a great FAQ on how to get started with that. Eating healthy, and ensuring you get all the nutrients your body needs to grow and adapt. Eat lots of eggs, fish, fish oil, anything with choline in it. Get lots of good sleep (which should not be hard). You need more sleep at that age, 10 hours is good.

The key thing is to notice the disconnect between mind and body, and work on improving your body mechanics so that it is aligned with your minds purpose. A particular problem I struggled with for most of my post teenage years was what I would call "neophilia" an obsession with something new. I moved from thing to thing never being satisfied. Satisfaction from hard work has to be imprinted through experience. The sense of accomplishment you get from achieving your goals (you have some right?) is something you want to nurture.