It's a relief to know that I'm not the only one who feels like this sometimes... but I still wish that writing and I could have a better relationship.
It's a love-hate relationship. I love to write. I hate my writing. I like to think that I can come up with a good plot, good twists, decent characters. And when I put pen and paper together and start scribbling out my ideas, I'm pretty satisfied with the results.
It's the computer that makes me angry. For a start, I don't like typing things that I've written on paper. But also, it seems like the computer makes my writing worse.
Example: I type out a nice, two-page story (or Topaz Adventures episode). As I'm typing, I occationally have trouble wording things right, making my meaning clear, and putting the right double entendre into areas that need more than one entendre. I correct, adjust, and fixate on certain sentances as I go, making the work take much longer than it ususally would but (I think) improving the quality of work. I love this part. It's mostly a pure flow of ideas, like my brain is flowing magic writing juices out through my fingers and squirting them all over the monitor.
Then I reread my work. I notice things like unvarying sentance structure, over-clarification of points, and overused words. I try to fix parts that seem rushed, slow, abrupt, or out of place. I focus on thing that I would never notice in anyone's writing but my own. It's like a puzzle, trying to fix all the things that are wrong. This isn't the part that I hate. This part's fine, just part of the process.
What I hate is that I'll do this over and over again. Every time I read my work, I'll see something that I did wrong, a place that the wording seems awkward or a group of too many sentances with the same, boring structure. Even when I finally feel I've reached an acceptable level of wordcraft, all I have to do is wait a week or month or a year, and eventually it will all seem wrong. It sometimes makes me angry when the people I ask to revise my stories don't notice all the glaring errors that I see.
That's part of why I like releasing Topaz Adventures as small episodes. I'm obligated to release them on time, so I have to put them out whether I'm completely satisfied or not. Which I never am. But once they're on the internet, I never have to read them again, except to check for and fill in any plotholes. It's nice to complete something and have no choice but to let it be.

Feels kinda nice to type that out, even though it doesn't really change anything.