Everyone is intelligent! There are at least eight different domains of intelligence, but school work typically assesses only two types of intelligence, Math and Word Smarts.
Math Smart - ACT
Word Smart - SAT
In order to be motivated in school and in life, you must recognize your intelligence and believe in your abilities. Focus on your strengths rather than your weaknesses.
When you feel good about yourself, you will soon discover that you can accomplish anything you set your mind to.