I tried a writing challenge a while ago. Story remains half-finished since I didn't think it was worth posting. I don't want to give people bad writing.Post in Creative Writing Challenge threads, and we will tell you.
Seriously though, I'm kind of in the same boat, I have grave difficulties evaluating anything I write since it's impossible to be objective, and I usually just default to hating everything I write because it's never as good as I aspire to be.
But "practice makes perfect" is a thing. I've only been writing "for real" for less than two years, and I can see notable improvement even today from where I started out.