That’s a very good question! Yes, it is entirely normal.
Hahaha, okay, so here’s the story of how I decided I was not too crap of a writer to live:
I read so much as a kid that I barely had friends. I wrote a lot too and, even better, I was surrounded by a little group of fellow writer-kids in my school. We were friends, I suspect, because we got it. When you’re 10, you don’t care if you’re terrible. You mostly don’t even realize if you are, because your sense of quality hasn’t been exposed to enough to get sophisticated. ^_^ It’s kind of a godsend.
But as I got older and began to develop a sense of good taste, yeah, I realized I sucked. And I think that at that realization, I largely stopped writing fiction (term papers were a different matter, of course) until sometime during college. But I kept reading, and eventually that led to my salvation. Here’s what happened:
I read a published, selling book that was of such a transcendent magnitude of total crap that I could not make myself believe I was a worse writer than that.
I can’t remember the name of the book anymore, but I clearly remember standing there, in the bookstore, with this POS in my hands and my jaw hanging open, thinking, “Jesus Christ, someone gave this person money for this?!”
I mean, dude, compared to this book I saw, I am frigging Shakespeare. I can write complete, grammatically correct sentences respectably free of typos just for starters, so right there I’m three points up on this epic accident of the written word.
And somebody out there gave that person money. Like, they thought there was a reading audience for this book.
And voila. I realized I didn’t have to be amazing. I just had to be readable. And apparently the bar for readable is really low, so on that day, I just stopped worrying about it. XD
(If you need me to help move the bar any lower, a couple of years after that, I came across a fantasy/horror novel—published! with a cover illustration and everything!—in which the first two chapters of the novel were blatantly plagiarized from H. P. Lovecraft. No attempt to even disguise. Cut-and-paste job. Man, that author had balls. And he got paid for it.)
Of course, later on it turned out that being a published author was not in the cards for me—not because I was crap, but because ARRRGH HOW DO YOU FINISH A FUCKING NOVEL THIS IS IMPOSSIBLE. But that lesson stuck with me. And it’s even more the case in fandom, where nothing is at stake other than the enjoyment of you and anyone who reads your work. You’ve got nothing to lose other than a few hours of your time, and I can guarantee you that someone out there is reading and enjoying your stories, so…why not write them?
So here, I can even assign you an exercise that might help. Writers dump on 50 Shades of Grey. If you’re having trouble making yourself believe that you’re worthwhile, I highly endorse reading it (don’t give anybody money for it, though, for God’s sake; borrow it from a co-worker or the library). I defy you to read that piece of trash and tell yourself at the end—or even halfway through—“I cannot do a better job than this.” And if you have to admit that yes, you can write a better story? Well, look how many people are reading 50 Shades. Many of them would go gaga over a, y’know, better story.
As for things sucking more the longer you write them, there are a couple of things going on there. 1: When you’ve stared at something for too long, you get sick of it. Your own writing is not immune. 2: The longer a story gets, the harder it gets, because you have more plot threads to balance and it gets hard to keep track of everything and it’s like those people balancing 50 spinning plates. 3: Rough drafts almost always suck. When you write something and then come back to it the next day, think of it as a chance to fix the things you didn’t notice the first time. Having flaws doesn’t make something irredeemable; it just needs spiffing. ^_^
Ira Glass has a fairly famous quote to the effect of: when you start out as a writer, you tend to have really refined taste in what makes good writing, but your skills in producing it haven’t gotten there yet. You have to give yourself time to suck and to get better. As long as you’ve got the taste, you’ll get there eventually, because you know what good writing looks like.
And many other writers have said things to the effect of: you have to learn to forgive yourself for sucking. We all suck on the first draft. That’s what they’re for. You just polish them up until they stop sucking so much. 🙂
This is one of the reasons I’m so big on seeing and showing writing process. It’s a huge boon, especially to new writers, to see the contortions we go through. When you’re on the outside, all you see is the gorgeous final product. What you don’t see is that we all go through the word-vomit first draft and the hair-pulling editing process and the screaming fits as the story stalls out and we can’t figure out what it or we or the universe is doing wrong. We all have the point in the middle of a story (which friends have coined ‘the valley of shame’) where what seemed like an amazing idea turns into apparent unending appallingness and we want to pitch our laptops across the room and scream, “GOD IS DEAD AND HE TOOK MY ICE CREAM WITH HIM! Fuck you, story. Fuck you!”
You get through that with lots of tea, a fresh pint of ice cream, a lot of black humor and maybe some friends to scream and bitch and beta-read your story with. And the understanding that sometimes, we suck and that is okay. ^_^