If you have had troubles passing classes in the past, why not find someone to tutor you, or talk with your teachers to see what they can do to help you.

Besides the classes, you are not alone in this, there are many out there that have felt like you, whither in the same situation or in different situations. I know I've felt like a failure, and alone. Just keep in mind that nothing can hold you back, if you apply yourself, and seek out help from your instructors.

Ask for help from those around you that CAN help you to pass your classes.