if you dont know what you want to do after a levels or what career you want i'd say pick maths, two sciences and maybe history.
maths and sciences are highly regarded and you enjoy them the most and your doing well in them. picking a written based subject like history broadens you future opportunities, your clearly good at it if your on an A and you can drop it after a year. you could pick 3 sciences and not do history but this restricts your university and career choices and may get very difficult and boring.