my confusions

It has been long going in my mind, that I have not been able to sort out my purpose of studies. The time I waited for eagerly for years to go for a Masters degree, came in 2004 when I joined USC. There were so many aspirations, thoughts, excitement and enthusiasm to learn and get a job. It all came to a disaster when I struggled with maths. There was so much interest to learn DSP. It all came down bad when I could not sort out my study method. I could not memorise stuff, could not retain understanding. I kept changing my ways to learn, but did not stick to one. I admit I did not resort to hardwork of solving problems which was one of the main reasons of not able to write exams. After the grades, I was disappointed and decided not to go further in DSP. I resorted to relating it to what I know industrially. But I did not have control over my subjects. I always wanted to take an OS class, but foolishly enough I could not do the projects in C++. I just lost the whole purpose of taking that class. Same thing happened with Multimedia class. It was very interesting, but I could not take control of it. Projects, I did with help of friends, exams I struggled with. It again defeated the purpose to an extent. But in a sense I learnt stuff and had exposure to so many technologies. Same thing happened with EE522. Its an A class, no work to do other than experiments, and a paper presentation, there also I goofed up. Professor was understanding, maybe he was disappointed but he gave me a B, most of the guys got an A. Again, I should have taken advantage of the class to get grades like others. At this stage I must have realised, this place is not meant for testing, take courses only when you are confident you can manage them especially when you know grades do affect your GPA. But even after an internship which was a boon to me, I still took heavy courses. I resorted to this reasoning, that since I cannot take Communications track ( random and other courses) I have to definitely take the computer networks track. I thought I must take CS551 to learn network programming and also had to take ee550. I was aware of my performance in cs402 where I did not work on the projects, still I took the chance of taking 551. It again turned out to be defeat of purpose if I did not do the project by myself. I had to take help from Paresh to a significant extent. I submitted late, was not able to study effectively for papers, and got poor grades. A disaster was ee550, when I just could not tackle the homeworks. It should have made me realise in the beginning that if probability was not my cup of tea in 1st sem, I must not take the same course again. After three semesters at USC, I still cannot say I was able to take control of even a single course. My diversion from DSP to networks track, again questions me if I cannot still be comfortable on software projects. The same fears which were there in my mind at the beginning are questioning me again. I was running away from Maths, but did it solve my purpose?
It looks good on my resume that I have taken very interesting courses at USC, but can I say I know all that stuff, No! I have lost self respect among friends. My GPA is bad and I am at a situation, where I may have to discontinue the MS program. More of all, I am taking extra courses to pass out. Who pays for all that money, my sister, father. Did education really help me? Was I sincere and honest? No, definitely not.
The same question comes back to me, you did not take use of the golden opportunity given to you.
At this stage, I am still perplexed, I always have this problem in taking decisions. I still cannot look confidentally at joining the industry, and still look foolish at academics. I feel guilty of making a fool of myself. On a positive side, I have learnt lot of useful stuff, and am better prepared to face my career ahead. But on principles of sincerity, hard work and truth, I am a failure. If I cannot do a tough assignment why take the course. If I want to accept a challenge, why not make efforts to complete it.
There are thousands who are deprived of such a chance to learn, grow and utilise an opportunity. I wonder, why am I not afraid of my situation at present. When it comes to speaking, I can impress anyone.
Why not then I also demonstrate my work. Why not be fair and honest with your work.