The first day of classes in my junior year, my second year of college, and my first year at a four-year University, I changed my major. I had done one year of Community college because I didn't know what to study, and it was cheaper than a four-year school. During that year, while I saved money, I didn't figure out what I wanted to do, but it allowed me to take more prerequisites, so that by the time I got to a four-year school, I was mostly taking classes in my major.
I wanted a good job, but all of the careers that guaranteed a job and higher income right out of college, didn't seem interesting to me.
So I settled on being an elementary teacher. I knew that the pay left something huge to be desired, but I would be able to find a job. That was my declared major for my junior year.
About twenty minutes into the first day of class (it was a elementary teaching class), while the teacher was still going over the syllabus, I decided to switch my major. I sat through the whole hour and a half class so as not to be rude, and while I sat there, I brainstormed what other major I could study. I settled on Communications because it sounded interesting, and I had a friend doing it and he liked it.
So as soon as class ended, I called my mom, told her, called my advisor, left a message with her, then went straight to the registrar's office. I am one of the few people who switch their major the first day of classes. So we switched my classes around, made a schedule that was more general/communication oriented, and took out all of the teaching classes. My advisor (who was a transfer advisor and not focused on only students of her department) got back to me, and I told her that I was a Communications major.
My reasoning was that Communications was something interesting to me, and that I could change my major again. People changed their major lots of times. I never did. I stayed with it and I loved it.
And while part of me still wishes I had dome computer science or engineering, I think that it's important to like what you study/do. I could never convince myself to study something for the money. Though I do wish I had desired to do something that paid well/had lots of job openings, I probably made the right choice. Besides, it's not very productive to go against God's plan, and with how bad I tried to get myself to major in something like materials engineering or electrical engineering but still couldn't, I was probably meant to be a Communication major.
So my advice to you, is to study something that you can see yourself doing for the next forty-fifty years.