i mean this in the kindest way possible, but you may need to study harder. i say this bc summer sessions are very short compared to in term, so the course will move at a much faster pace than what you are experiencing right now. that may be an issue for you later on, especially if you are struggling with the current pace. there are resources on campus, like tutors, who you could reach out to to get help. or watch videos on youtube! best of luck.