Wow, this is long! I will just go over the first paragraph for flow and style. Maybe you can use it as a guide for the rest, or maybe someone else can pick up the second, or maybe I'll be back later, or maybe cows will fly in from the moon, or maybe...
Your overall structure and organization is very good by the way, but I would add an introductory outline paragraph introducing yourself, explaining this document, and mentioning the schools name as your choice for education.
I can't understand this
::::In 6th form I took Media Studies, History, and Philosophy & Ethics. I achieved B grades in all three of my subjects at A-Level. I feel that my success was chiefly due to a good ability to meet deadlines, and work in groups when it is necessary. Throughout the two years that I studied these subjects, I became increasingly interested in the English language. Therefore my goal for university is to be able to expand my ability in, and understanding of English by choosing it as my major. As I may choose a career in the media, and I feelit would really benefit me most to learn about the various ways in whichEnglish can be used day to day, and in various social contexts. This also interests me greatly.
please explain what also interests you greatly!
As always, these are only suggestions, so don't follow this blindly without deciding whether you think you like it better. Your writing is quite high level, and as such there are many edits I have made which are not corrections but subjective questions of style.
No more time for now, but good luck with the rest!