i think English lit is a really good option as it links greatly with your other subjects of psychology and history which are also essay based, and since you like doing context, which at times is 50% of the paper in most exam boards, I think you would be strong at it. Personally Eng lit is my therapy subject and I really enjoy it despite not having the best teacher at school, if you study popular texts its really easy to find relevant resources online, plus if yorue good at providing original interpretations thats even better as examiners are all about looking for unique interpretations. As for time management, its something you learn along the way because youve got full essay questions so it gets easier, especially if you have studied the text thoroughly. For maths, perhaps if your base isnt strong enough I wont recommend it, as it seems the only reason you want to choose it is due to taking further maths and some of the topics being relevant. Good luck with your decision!