Hang-Up on Grades and Level of Performance

I think that this might be the correct forum to post about my obsession with grade and having to excel.
I am a perfectionist and idealist by nature. So I always want to reach the peak in all of my endeavors. I am gradually adjusting my goals.
I am currently a doctoral student at St. John's University.
Throughout my life, I had been obsessed with getting straight A's and into an Ivy League university. I lived out my high school years with the sole purpose of getting into an Ivy League school. My worst fear was that I would be stuck with only getting accepted into Rutgers (my state school). I have never really gotten straight A's in one semester in all my schooling, but have gotten close at some points. It was hard for me also because my brother is a brilliant overachiever and was the valedictorian of his class. It always hurt me when everyone compared us and commented on how different we were (since I thought it meant he was smart and I was not). No one has put more pressure on me than myself, however. My worst fear ended up coming true when I was just accepted into Rutgers University and was stuck going there. It is something that I still have not fully gotten over, even twelve years later.
When I was in college, my professor told me that he has never met anyone as grade-obsessed as me. It was true. The worst part was that I did not even end up getting the grades that I wanted despite being obsessed with grades. My college GPA while applying to graduate schools was 3.5, and my final college GPA (after slacking off when being accepted into a graduate school) was 3.45. My worst fear during college was that I would not get into any PhD program. However, I graduated college in just three years (one year early).
During my master's career at Stony Brook University, I did better than I have ever done. I got majority of grades in the A range and just 2 grades in the B range (out of 10 courses). I also got my master's degree in one year, at the age of 22 (when most people get their bachelor's).
However, my worst fear again came true. I did not get accepted into any PhD program, just a Doctor of Arts program. I do not know how that would make me look as a candidate in the job market.
I have also not been doing as well as I have liked in my DA career. It was easier for me to get A's during my master's than it was during my bachelor's. I had a 3.75 GPA in my DA career at some point. However, now my final GPA is 3.58. I am done with coursework and working on the dissertation so my GPA will not be changed from now onwards. Sometimes I feel really bad that I did not get straight A's in my doctoral career. I hate it when people say that a B+ is a horrible grade or that they cannot afford to get less than an A for the reason that I am trying to convince myself that grades are not so important, but other people's anxieties over grades are continuing to push me in the direction that grades are important. The one B+ that I really regret is in a Medieval Romance course. It had always been my dream to take a Medieval Romance course, and I think that I even convinced the professor to offer a course in Medieval Romance. I did other things above and beyond for that course. And I put in so much time and effort into writing an exceptional final paper, which explored complexities at many different levels. However, the professor still assigned me a B+ for the course. I did not agree with any of her negative feedback. I was depressed over the B+ for months. I am still not completely over it.
I have also very high goals, aiming for the very highest. Earlier, I had on my list the following career paths to pursue: a professorship in English literature, an actress, a model, a ballerina, and an opera singer. However, now I am trying to determine why I want those careers and whether I am really interested in all those careers or just excelling in them. I have more or less taken off being a model as a career pursuit. It was not really something I ever had much of a passion for. I just wanted to be a model since I thought that it would prove that I was the ultimate in beauty. However, now I know that you need not be a model to be the ultimate in beauty or completely comfortable with your appearance and also that models are not always the ultimate in beauty. In addition, since the career comes with so much rejection, I did not think it worth it to get the rejections and lower my self-esteem when I did not even have enough of a passion for modelling in the first place.
I do, however, have a passion for acting, singing, and dancing. I have been taking acting classes for a long time, have been in some shows, and will approach auditioning full-throttle once I am done with my dissertation. I started singing later than acting so I am not yet as skilled in singing. Right now I have to work on mastering following pitch. I had wanted to become an opera singer before because opera is classical music and is sung by the best singers. However, now I do not think that I should really pursue opera just because it would prove that I am the ultimate as a singer. I will pursue opera as a hobby for now and decide whether I really like it that much. People say that at my age, people already have a career set for years and it would be nearly impossible to get a career in opera after age of 30. Sometimes when people tell me that something is impossible or close, I want to pursue it just to prove them wrong. However, I really need to consider whether I am interested in the career, itself.
I also had a dream to reach the peak in a career in ballet. Again, I am trying to consider whether it is too idealistic. I am 30 years old and started learning ballet from scratch just three months ago. By my age, several ballet dancers have not just had a career set, but retired from it. The majority of ballet dancers start training from the womb. I had posted on Yahoo! Answers about advice about starting a career after starting from scratch at this age and was very down when I received so much discouragement. However, now I have decided to do what is realistic instead of aiming for the highest just for the sake of it. I will try to learn to enjoy ballet for the joy of dance, itself, and will work my way upwards from there. I will stop wasting time calculating the odds of possibility for what I want with ballet and will instead invest that energy into getting better in ballet.
So I have decided to do the following. It would be a waste of my education in English literature if I just pursued acting, opera, and ballet as careers and had a day job as a waiter. So after I get my doctorate, I will pursue a career in academia. I will continue to pursue my other dreams in my free time. I will audition relentlessly for theatre and film roles. I will keep on training in ballet and opera to find myself in what I want to do in them. Maybe I can also do some modelling just for fun. I will use my successes in everything to build up my self-esteem and achieve the next success, whatever it might be.
I have also realized that in achieving my goals, I have good ambition, inspiration, and dedication, but have to work on my motivation, confidence, and putting in my very best efforts.
So this will be the journey that I will take from now onwards. Please share your thoughts and feedback.

i actually just admire you and what you are doing...
i am so far from it.