Another fear of mine: writing bad stuff. Then I look at how much I wrote in the last 2 years:NOT ENOUGH! My fear is actually not baseless, in fact it's almost guaranteed I'll put out a lot of bad writing because I did not pay my dues.
The solution: accept it and write even more.
Every sentence bring me closer to writing better, at a level I'll be comfortable saying: I'm a decent writer.

Good luck!