How is going to college helping me Please read my details?

Im 19 and going to college out of state. I live with my brother and paid my rent in advance. Im going full time and can barely keep up with my grades. I dont have a job. i am interested in fliping houses. I know roofing texture drywall and rought carpetering. I know landscapeing and my brother is a carpender and a plumber (workign on license). I like working and not doing it is killing me inside. I Want to retire and want to work for myself. I want to see what i do effect what i make. I love business and am confident i can run one. I lack the money to start up and am not earning anything right now. I feel that going to colledge is wasteing my time because i could be doing more. Right now going to school is not helping my goal of owning a business its only going on paper, I heard that going to colledge is useless if you dont know what you want out of it, I Wont quit at this because i Hate quiting. How can i work partime to make a business (importing nan I have some words to encourage me