Is it worth it?

I got my AS results today and I'm kind of worried, I want to do something economics related when I go to Uni however my grades are putting me off now, I got a B in Econ, D in maths (had a feeling it would be horrible), E in English lit (was not expecting that at all ) and U in accounting (hate the subject). I'm definitely retaking maths and eng lit because i'm 100% sure that I can push those horrid grades up but the courses I want to do require AAB-BBB, assuming I get something like ABB or BBB, is it worth working hard next year? I've even forced myself to self teach next years syllabus during the summer.