I've been writing and performing poetry for a couple of years now, and i've certainly gotten better at the dealing with the feeling you describe. I found the more I performed and got audience feedback (not necessarily what people said to me after, but how I felt about the performance - you know when you're holding a room in the palm of your hand) I got a better handle on what's good or not. Poems I didn't mind, I started liking. Those I disliked but knew worked, I started to be proud of. I'm still my own harshest critic, but I let myself off the hook a bit more now. Don't get me wrong I will always write quite a lot of shit poetry, and I'll always find myself crippled with anxiety if I've written and want to perform a piece outside my comfort zone, but I've made peace with that for now. I really hope you figure your way out of these feelings and find joy in your writing once again!