Well, I don't think you need a degree in Accounting to do ACCA.
Start from school, am talking about SC and HSC.
Difficulties in ACCA? I heard from the others it was pretty easy... Well, everyone have their own views. I was advised to do ACCA first, then pursue management.
Economics, you know what? When I took this subject in Form 4, everybody was telling me: "It's the bulkiest syllabus that you're taking, Eco is so heavy, it's so dynamic, always changing, bla bla..."
Yet I took it, cause it was a subject I wanted to do. Yes, Eco needs A LOT of analysis and application skills. But there is absolutely no reason why you can't do it. Eco is 'common sense applied in business, political, and social issues'.
If you think you can do it, do it. But if you think you cannot take the risk, you still have many other subjects. Accounting is one of them.