Okay, well let's start with a meta lesson I learned in college. It's not to late to change your mind and switch directions. And if you do, there is a price to be paid.
My first major in college was Computer Programing, Math Option (that's the hard one). I was pretty good at both (programming and math). Hell, I won a full ride Air Force scholarship for it. I was admitted to the Honors Program and choose an eclectic alternative general studies program including a minor in Creative Writing. Then came my sophomore year and my life decided it was going to go to shit. By the start of my Junior year I was out of the Air Force and had switched majors to Graphic Design.
It would take me another four years to finish my degree program. I would be working four jobs and taking our loans to repay my scholarship and afford to live at school (and afford school). I would get permit slips from my professors to work in the art building overnight (to do my coursework as my apartment wasn't large enough and I couldn't afford a table of my own). After a decisive event (which will be the subject of another post) I got the fire in my belly and while I didn't graduate with honors (the fallout from the self destructive cycle of my sophomore and junior years) I ended up in the last two years being on the Dean's List at the very least (and in a good way). I made President's List three times.
I didn't take art classes in High School. I had never done much more than cartoons and simple sketches before this. But with hard work and applying myself I excelled in design. It did help that I had interest in the field and a slight aptitude for information architecture. One of the first things I would learn with a new programing language was the output functions (this was in the time before GIU computing) and I would format and label my output.
I changed my life. I paid the price for that change and I worked hard for the change. But I did switch majors and I've had a somewhat successful career so far. So it is possible to do new things and be successful at it.
The other lesson of this was that I wasn't very successful at first. Eventually with that hard work, acceptance of critique, progression of skills, and continuing to learn (heck, I've been a professional visual communications designer for nearly twenty years and I'm still learning new things), I became good at what I choose to do. I can do the same with writing fiction. So can you.