I've been where you are, and we're not alone!
My advice to you is to trust your intuition. To constantly be wondering about whether or not you're getting things "right" will cripple you. No matter what career you pursue, you'll face challenges and failure along the way. But that won't necessarily mean you're not cut out for that career. That's just life :) Nothing is perfect, and there are no guarantees.
Remember that you're allowed to change course. You're allowed to decide, after months or years or decades of being a nurse, that you want to be a blogger or a chef or an accountant. There are no rules saying we have to stay fixed in one career for our entire lives.
I'm a living example. I majored in journalism because writing is my passion. I worked as a reporter for 15 months, and then I felt called to teaching. So, I went back to school and became a teacher for three years. Then, I decided I needed a break from teaching, so I went back to writing!
You're wise to consider whether or not your decisions are the best ones for you, but I caution against putting too much pressure on yourself. Follow your passion, listen to your calling, and trust that you'll end up exactly where you need to be. Give yourself grace if, in the future, you change your mind.
Best of luck to you, Emma.