I'll be guilty to myself and admit I'm struggling with a similar decision. Or was, anyways.
I just transferred colleges and though it took a while, I decided to "let it go". I have three years left here - it gives me a long time to truly decide what I'd like to do. I'm (hopefully) getting involved in a biogeochemistry lab (studies nutrients in water and how it affects the marine life kind of thing) and volunteering at a hospital - right now I'm not certain what I want to do, and for once, it's actually reassuring.
I know it's stressful, but please take care of yourself - my younger sister is going into her senior year of high school and is having breakdowns from the stress of having to make so many important decisions. I simply made them by ignoring them.

It's how I ended up at a community college.
I know if I do decide vet later (say my senior year) it'll be a rush to get experience, etc. But..it's really not going to kill me if I take an extra year to try to work full-time in the field and decide it's exactly what I want to do with my life. Right now I'm leaning towards research...I live in Washington, and marine biology has always fascinated me. I think it'd be useful to study what's going on up in the Salish Sea where the orcas live (plus I love cetaceans. So much.), particularly concerning their food supply. It seems dry to everyone else (I get lots of blank stares), but hey. More room for me.
I guess bottom line...try out both. Not just once, but try to do it continually. If the vets/physicians are catty, focus on what they are
doing, not just what they act like. Is that something you could see yourself doing? It's important to get right down into the nitty gritty, I think.