This might be a bit incoherent, and not providing one single problem to give advice for. Just let me get this off my chest.

This is one of those moments in my life when I'm worried about my future.

I'm 21 years old, and in the first year of a (two-year) curriculum for a Master of Philosophy degree in linguistics, majoring in syntax. I love the field, because language fascinates me. It's hard work, but I'm keeping up well so far. You'd say things are looking up. But I feel some anxiety about where the whole thing is taking me.
The curriculum I'm following is focused on preparing people for academic research. The thing is, I'm not sure I really want to go into research. If I could pick my choice, I think I'd prefer a steady job that I can handle without too much trouble. Not something as confusing and competitive as the academic world.
Then how did I end up there? Well, it's a bit complicated. I started out doing another master, but it turned out that curriculum was dying out because nobody else cared about it. Then one teacher (whom I trust) advised me to go do this one instead. Since the contents are basically the same, and the level of difficulty being higher might be the greatest difference, I figured I should give it a try in a fit of optimism.
I still don't think switching was a bad idea per se. I've also recently learned that courses that are dying out are not the best ones to follow; the teachers might not really care about them any more either.

But my current research project assignments intimidate me. I've done one major project for my Bachelor's degree now and I'm working on one to conclude a course with, and each of those went wrong somewhere and ended up sloppy and generally half-assed. More specifically, they both went wrong multiple times on the part where I should agree with the teacher on the formulation of the research question; in both cases I ended up having to adjust it many times, often entailing even that I had to think up a new plan around the stuff I'd already done, or start all over again with no guarantee of not encountering the same problems. I hated that. And needless to say, projects that are made like that are neither the most coherent nor the most interesting ones. Thus my apparent talent for misunderstandings makes me seem mediocre, while much of the time and effort I put into these projects are wasted on things that won't make it to the ragtag final version.
By the end of this year, I'll need to have one more grand project finished, and by the end of next year I'll have to pull a fucking dissertation out of my derrière. I'm really not confident if I can actually do that. I'm worried I'll encounter the same frustrations.

And if I manage to pull it off, then what? I'll have a very prestigious but ultimately useless degree that, outside the scientific community, won't mean much more than general academic skills.
I'd be incredibly proud of myself if I do get this degree, but meanwhile I envy people who study something they can actually apply in real life and get paid for. Medicine, IT, law, psychology, that sort of thing. All I can do is draw purdy syntax trees and explain the current views on the technical reasons why "I care not" sounds weirder than "I do not care".

Try to apply your proffesion. Get creative and try to image how can you get paid for it. It will motivate you and you will be doing something that anyone else has done, so it's probably you'll get an own business and have plenty money until another person tries to imitate you.

Good luck, i say!