Seriously strawberry person, get over yourself.
People get into Oxford all the time with much lower GCSEs than you. In fact, I would suggest that you had a lot less to prove in your interview than they did theirs, as your academic worth (which is very clear to us all by AAAAAA!!!) is very visible on paper. The other people have to prove their academic worth, while you just have to confirm yours (i.e., what seems to be apparent on paper). The interviewers you had have more than likely been interviewing for years, and will know how to pick a candidate. And if they think you're good enough for Oxford, they make you an open offer.
The fact that you didn't get in after two interviews already, and despite your academic results, suggests that Oxford is perhaps not the place for you. I'm not discrediting your ability at all, but people often have a much better 'experience' outside of Oxford, and do just as well. If you really think you're the best, then go to LSE, UCL, Durham or Nottingham and come top of the class. If that doesn't sort your career out, nothing will.
As a point, less than 50% of partners at Magic Circle firms are Oxbridge educated.
20% of barristers are not Oxbridge educated. Once you allow for the older generations and years of intake of barristers that are >90% Oxbridge, there is a very large number of non-Oxbridge-ers at the Bar.
Not being Oxbridge is not life-ending or career-destroying. People are aware of the fact that Law is bloody competitive, and that Oxbridge admissions are not perfect. People who are good enough and dedicated enough succeed. Look at Cherie Blair; the only person ever to first in every single module at LSE Law. Clearly good enough for Oxford; did just as well anyway and became a barrister.
Anyway, don't let the rejection get to you. I saw people get into Cambridge with much worse grades than me. But, I accept that they were probably far more suitable for the course, and take comfort that if I wasn't suitable for the course, the course would not have been suitable and enjoyable for me.
Just accept it, and good luck with LSE!!!