Most important thing to realize is that everyone around you sucks ass at writing. They just care less. In my experience, the people who don't hate writing are also the ones who are usually really bad at it and don't realize it. So you already have your doubt going for you.
I also suck at writing, and I try to counter that by taking my time. I usually write best late at night.
Writing gets much easier if you know what you (don't) wanna write about. Sounds obvious, but sometimes when you're stuck, it helps to read/talk/go for a walk and think about it without distractions. Clears things up for me very often.
And lastly (also obvious, I guess), doing it structured and somewhat iterative also helps. Make a bullet point outline, fill in the blanks.
But I assume you already know the above. You just need to realize that the fact that there's lots of good writing out there doesn't mean it's easy for everyone or even anyone.
