I'm a sophomore in college and just changed one of my majors (I am double majoring). For me, it was stressing me out so much because I felt like "Oh my god, I'm a sophomore! I'm supposed to know what I am doing with my life!" Which I have come to learn is a ridiculous expectation most college students believe for themselves. It's ok to be undecided until you 100% know what you want to do, or even just have an inkling. It's ok to change your major halfway through the year, why stay in classes that don't work for you and that you're not interested in?
We all put so much pressure on ourselves to know what we want to be "when we grow up" but, even if you've thought you wanted to be a vet forever, you might start taking vet classes and hate them. This is nerve-wracking because it sort of shakes your beliefs. You thought you wanted to be this one version of you forever and suddenly you can't picture yourself doing your dream job. But, you have to think about it this way: would you rather take the chance, change what you know and end up doing something you absolutely love? or do what you've always seen yourself doing but resent it?
Don't worry about how long it might take you to graduate, how many classes only count as electives now, or think about time wasted. Time is never wasted, you took those classes, and though they may not count towards your new major, they taught you that your past major wasn't for you. If you're thinking about switching your major, do it. If you were happy where you are and doing what you were meant to be doing, you wouldn't second guess it.