If I had to put my finger on the exact time these emotions started, I would have to say it was when I moved and entered a new middle school. Due to a error by my new school, I was not put in any accelerated courses. I was able to finally catch up to where I should have been in my senior year of high school.
I am currently pursuing a degree in Physics. The bad grades started two semesters ago. I overloaded myself with two physics classes, a chemistry class, and Calculus 3. Normally, I would be able to get A's in a class in spite of my lack of motivation because I would cram the night before and get good grades on major tests. However, I was not able to do this two semesters ago because of the sheer volume of material. I received my first C's in college. Last semester I thought I could get serious about school and redeem myself. Once again I took many difficult classes -- three 400-level physics courses and a math class. By the end of the semester I withrew from one class, failed Physics 411, and got C's in my other two classes.
I have tried many different possible remedies, but I have not been able to shake this laziness off. It seems like I stopped caring about school. I can see possible reasons for it. I lost a brother some years ago and as a result I spent a lot of time and energy thinking about life. I also think that I might have some confidence problems after being forced to slow down in middle school. Both these events took a lot of my time and energy and I feel drained because of them. I'd like your advice.
I was never a Physics major, but I question taking a lot of very complex courses simultaneously when you are in a confidence crisis. If possible, why not take only one or two very challenging classes at a time while you receive on-site assistance with your study skills? If you do well at one class that has been difficult for you, then that alone will boost your confidence level.
As I understand your comments regarding your middle and high school years, you may not have received sufficient academic preparation for the demanding major you are now studying. A meeting with the Physics department chair on how best to adjust your curriculum to your needs and what classes you may need to retake to improve your skills may be a good idea if you are thinking that your college prep classes did not prepare you for what you are dealing with now.
I am also concerned that underneath your expressed lack of motivation may be some depression. The loss of a sibling is devastating for a young person. Sometimes the full impact of losing someone in our family does not occur until a later crisis point in the survivor's life -- for you, this may be now, during your college grade difficulties. It is acceptable for a young person to spend some time "thinking about life," but when this is accompanied by apathy, lowered energy level, and a lack of effective coping skills -- you may be experiencing some underlying depression. Most colleges provide some counseling services for students' personal issues. I hope you will look into this. Consider it as part of your overall plan to improve your grade problem. I really think your low energy level, study skills, and your past and current emotions are tied together at this point. Each area demands some intervention in order to improve your situation. Thank you for writing. Please get back to me if you have further questions about this. Good luck.