Sleep and have fun.

Seriously - as far as I can see, the leading two reasons for a student, barring personal/domestic/psychological/developmental issues, to not do good in high school is because they don't sleep enough and they stress too much.

So instead of staying up overnight to study, go over your notes then go to sleep. Instead of studying your notes one more time "just in case", go take a relaxing bath and clear your mind. Your subconscious, passive memory is better at remembering things than your active memory. And it'll stick to you longer.

Of course, if there's any other issues, fix them. Is your mom stressing you out? Talk to her in earnest and negotiate some calm. Go see a doctor if you have physical or psychological troubles. Uninstall that fucking game if you get mad at it.

Also, stay away from substances - marijuana, alcohol (and I hope for your sake that's all I should have to suspect...). If you're prescribed Aderall/Ritalin/Concerta, keep at your prescription - don't forget it, and don't take more. Even coffee - it robs you of sleep without the benefits of it.

And, of course, pay attention to class - no, not even. Be ACTIVELY present in your classes. Ask questions. If you feel you don't understand something, ask for extra exercises.

With all of these, you should have less problem passing. But don't give up. You WILL go to college if you will it.