This is definitely a good question, and although I agree with aspects of the other professionals that have answered, I'm going to take a bit of a different approach because I think it's important to see all sides. I also think there is a bit of a catch 22, when you're first starting out in your career, and I'd like to address that here.
I've been working as an Illustrator, Designer, Graphic Artist, and Art Director - for about ten years, combined - and I've found that because I had a breadth of interest (as it seems you do, as well), it was a bit harder for me to narrow down WHAT I wanted to study and major in, because I was interested in many things. However, I took some time to think about what it was I wanted to do in life, and I knew it surrounded the Design field, so MY focus was on a major called Illustration Design. The reason I chose this program, was because it allowed me to focus on a broader spectrum of artist focuses; I took color theory, illustration, figure drawing, graphic design, perspective, english, AND cross disciplinary classes like advertising, etc., that allowed me to stay in my element, but get some experience in other areas of art too!
Now, the reason I'm explaining all of this (let's make this long story, longer :p), is that it was important WHEN I graduated, that I had school experience that fit what I wanted to do. I totally agree that you need a strong portfolio, in fact the portfolio is the key, but when you're first starting out, you don't usually have very much work experience to show prospective jobs. Here's where the catch 22 comes in… sometimes it feels like you need to have the work in order to get the work! (which can feel frustrating - but, fear not), you need to have a portfolio that supports what your style and quality of work IS, BUT, the education really does help inform whomever is hiring you, that you have learned the skills that are required to execute the job well. It may not be a deal breaker, but coming from my industry, you may get asked why, and you may need to work a little harder at the beginning to show that you have those developed skills. I might see a beautiful portfolio, but ask myself, "Can this candidate manage her time? Can I toss her into a working art department and be fairly certain she can execute her work because she was taught the basics of development, and not just how to make the final product look good?" Having the education to back up your portfolio helps align YOUR image, and it presents a clear view to whomever sees your work.
With that said, I think it's important to explore and experiment while in school. If you love English, maybe find a way to do a double major or take a work load that really allows you to learn both; you may find that you'll grow to like one more than the other! If you do that, I'd suggest taking classes in design that allow you a bit of breadth. As an example: Graphic Design requires a huge understanding for space, balance, color, type, layout, etc. Nail the basics in the classes you take. Try experimenting with other areas like UX/UI - this would give you an advantage in the job market.
If you're just starting out in school, experiment! If you're nearing the end, try committing to something you're excited about and really learn it from the inside out. There WILL be time to learn more in your career, but it is a bit more difficult to make a 360 turn from say, nursing to graphic design. But hey! I've seen it happen. We will always keep learning in life, no matter what!
Hope that helps :)
Creds: 10 years of experience in apparel/design
School: Art Center College of Design