dropping Chem

Hi guys, I want to do Psychology at Uni. Most unis say one or two of either Bio, Chem, maths, psychology and physics. Right now I do Biology, Chemistry, Psychology and, Classics and am thinking of dropping Chem. It's not that I dislike it but it's more that I feel I have more chance in getting grades like A* A A without the workload of Chem. Some friends say drop others say don't. Even my parents don't want me to but I don't think I can handle 4 subjects in year 13 (from September onwards).

What should I do?