Marketing and/or HR

Ever since I started my first semester and I was facing this real dilemma. Im still not sure about what should I go for! Im doing my Masters of Business but I haven't still made up my mind whether I should go for a single (Marketing or HR) major, or have a combination of both but ending up with no major.

I have taken a course in Marketing, and not only completed it with a distinction but I really enjoyed it too! The only thing that scares me with the single major kinda thing is that I don't want to be stuck and have to work in one field. I keep getting those 'what if' scenarios that drive me crazy and add to my confusion! What if i don't like working in Marketing.. or what if I find HR boring!!

so can anyone especially those who -WORK (and not study, cause there's a huge difference between the two) in Marketing or HR-, HELP, please!!