Im sorry about how your feeling but im sure you'll be surprised - you sound like someone who is very confident in english anyway so you couldnt possibly done as bad as you think you did - i mean, your under exam conditions, your not able to properly sort of reflect on the quality of your work. can i just say, i studied King Lear for critical and like most of my classmates, was really relieved with the question - i agree, it was easy. But preparing for it was not - unlike texts like wuthering heights etc i think the kind of questions they can ask about Lear are really broad - anything from focusing on scenes, characters, making your own production of the play. i was really worried walking into the exam for that reason.
