If you are considering teaching, is there any way you could do volunteer work in a school? If you go in every once in awhile and spend time there and talk with teachers about the pros and cons and see what a "day in the life" is like, it may have an influence on your choice
On top of that, if you do decide you'd love to be a teacher and get your degree, I'm sure some volunteer work on your resume could put you ahead of other applicants! I'm not sure what kind of volunteering you could do, if any, but it wouldn't hurt to look into it!
Personally, I switched what I wanted to do too, and still don't know what I want to do! I thought I wanted to be a pharmacist, but the competition to get into the college and limited funds meant I had to switch to something I knew I could get into immediately and finish. I was always good at math and science so I switched to Engineering
After a year and some more financial setbacks, I switched to a smaller tech school to take Engineering Technology. After 5 years of work I am glad I just took the diploma course and not a full-fledged degree, because I know now this isn't what I want to do for the rest of my life!
So I totally recommend research and volunteer work or job shadowing before you decide!