Employers tend to much prefer a major in CompSci if you’re looking to be a front-end developer. A compsci minor still tends to lack in terms of employers preferring actual compsci majors over someone with a minor. CompSci have deeper aspects in terms of programming and theories, Interactive Media and Web Design is just that, designing and making media. Though it’s sort of a subfield to compsci, it’s skimming the surface. You can demonstrate that you know deeper aspects of the subject when you possess a CompSci major over the one you currently have.
Furthermore, when you stated that you are bad at math but good at art, that is exactly what employers see with a CompSci minor. It’s similar to getting a BA in CompSci, you will be better at getting a job with a BS because it shows you possess more technicality.
If adding on semesters is an issue, I would look into trying to switch to a CompSci major, and see how many classes you can transfer over and ditching the Interactive Media and Web Design minor altogether and just focusing on your CompSci major might be a better option.