Write more. And remember that everyone who writes anything good wrote a lot of bad stuff first. You are learning, be kind to yourself, just as you would be kind to anyone learning to do something hard, like juggling or ballroom dancing or surgery. Learn from your mistakes, and get better, and one day you’ll write something you won’t loathe.
(Also, it’s fine to dislike something you’ve written. But don’t dislike yourself for having made it.)
