Have you been tested for a LD? Those kinds of tests measure your IQ and then compare it to your scores in specific areas (memory, spatial reasoning, etc.) as well as grades. You can do very poorly on tests and still be very intelligent. If the scores don't match up, then likely, it is a LD or something else, not your intelligence that is holding you back. I think it might be helpful to get evaluated.

As for school, have you tried tutoring? You said you like to watch movies. Is there any way that you can take the things that you enjoy and incorporate them into your learning? Such as watching a documentary about a specific subject or watching tutorials on how to do math problems? Have you tried talking to a counselor at your school?

Don't give up... people with ADD and LD can be very successful. You can do it!