Having a lot of trouble in school?

I'm really having a hard time sleeping every day, and I just can't just fall asleep. In school, I have a lot of trouble concentrating and focusing while doing homework. I have a lot of a trouble in languages because when I write, my ideas don't follow up. i mix up numbers in math(23 and 32 for example) and even numbers too, I could think that 68 was 64. And this kind of mistake really disavantages me. I have a lot of trouble too while reading I have to read a page atleast 5 times before understanding what the main idea was, It takes me about an hour to read 20 pages. I keep shaking my feet while sleeping and in class and I'm also daydreaming a lot and staring at windows and imagining stuff. I have a hard time organizing my tasks and do everything last minute and just play video games. Homework is just too hard for me, I do it all the time, but just can't study. I can't study many subjects all at once it's just over what I can do. Example, .i'm going to have a math exam tuesday, physics exam thursday, english exam friday. .it's quite impossible for me to survive this. I'm always below the average of the class even when I get a 85.

Here are my grades

English 85

Physics 73

Maths 77

Biology 53, memorizing stuff is literally hell

Drama class 56, forgot to give away some work

Phys Ed 84

French 62