For psychology either comb. will be fine, the second maybe a little better. Maths might be useful too, maybe sociology. Do what you'll enjoy, if you think you can get a good grade in it. Chem isn't necc. for psychology. I get the point that Chem is better for sciences but then you'd probably want maths too, depending on where you're applying. It's difficult at A-level to keep routes into science and arts open at the same time - you really have to make a choice.
Don't worry about not having done History. I'd not done it before A-Level (I'd done Class Civ, which is a lot easier) but I was fine. You've done eng lit/lang at gcse, so will have the essay-writing skills you need.