Hi there, sorry about your situation. let me cut to the chase: there are lots of study routines that many students use. However, not every study habit can work for same two students. You just have to find your unique way of studying. I believe that success in passing the course depends on 2 factors: the quality of the professor (and his/her attitude, time management skills, and organizational skills) and, of course, your desire to put in effort in studying and using appropriate study habits that work for you. I will assume that your professor is organized, and clear in his/her expectations and grading criteria. To study for exams you can try the following:
1. Ask the professor if study guide is available. If not make your own. Now that you have taken a few exams you know what their format is and what is likely to appear on the next exam. Having that in mind, create a 1-2 page study guide with important terms, concepts, diagrams, reactions etc.
2. Every day, try to spend at least 30 minutes going over the material of the previous lecture(s). You need to have that information internalized. This way you do not have to cram all of the material on the night before the exam.
3. Remember, your goal is not to memorize and then forget. You have to understand how A clicks with B and results in C. For example, you are studying acid-base neutralization. Read the passage and then stop to recall information in your own words. Make a quick sketch of what it looks like, a diagram, something visual.
4. Whenever you feel you are failing, do not wait till last minute to speak to the professor. Go and speak to him/her. Ask what you can do to improve your study habits. Is there extra credit available?
5. Finally, on the day of the exam, spend another 30 minutes to go over the notes. Breathe. Pop in a sweet drop to give you that glucose rush.
I hope this helps!