Considering that you want to pursue business at university, I would suggest that you not drop Econ entirely but rather downgrade to SL. This way, you are still learning information that could prove to be useful when university comes but the workload becomes lighter. However, if this would still be too difficult for you, I would simply suggest replacing Econ with a subject that you are overall better in. This way, you can boost your average/GPA to look better for university applications. Hope this was useful and good luck deciding!