Be very very careful about not to jeopardize your F-1 status. Get very specific infortion from the registrar and international student administration office about what to do for what held true yesterday may not be good anymore. I believe if you drop a class while taking minimum full-time class. You will be out of status and if you fail any course once or more than once, you face the risk of being out of status. Get info from international student office at your college. good luck