Did you honestly explain the circumstances to the teacher and suggest that you get a failing grade on the essay or so type of punishment or did you just deny responsibility? Your problem is that you are guilty of plagiarism and if you tried to defend yourself as being innocent you just convinced her to punish you more. Apologize to her and to the person the offense was reported to and try to get a lesser sanction. As to her comments about your faking your illness, if she said that it was her opinion you did X as opposed to saying it is a fact that you did X, it is not actionable slander. In any case, it is not worth while to sue or demand a retraction.
