Allow two hours of study for every hour in class, but adjust the hours as you find out how long it takes to master your assignments. Plan blocks of time. Allow time for sleep. Sacrificing sleep to gain time for study starts a vicious circle. Eat well-balanced meals.
Dietary deficiencies result in lack of pep, irritability, and fatigue.
Double your time estimates. Start your long jobs ahead of time. Make a plan for living. Your schedule must be a plan for living, not merely a plan for studying.