SHORT ANSWER: Suck it up. By aspiring to make it as a writer you’re implicitly saying that you’re one of the 1,000 best writers in the Anglosphere. If you’re not willing to own that, there are hundreds of other writers who will.
That’s true advice, but it’s also unhelpful. You’ve heard it before. If “sucking it up” were that easy, people wouldn’t need writing coaches.
A LONGER ANSWER:
There’s a certain kind of artist who is immune to criticism. No matter how hard, mean or wrong the note, they take it in stride. These people are rarely great in their field because improving at writing requires insane commitment and the ability to care.
The point of screenwriting is to create something that can be read and enjoyed by many, or at the very least by someone who can offer you a job. A script that doesn’t help your career his failed. This is a long process. Notes and feedback are how you learn, how you develop. If you never let a note affect you, you’ll never improve as a writer.
Caring is hard. New writers often write with a layer of protective irony.
NEW WRITER: The script didn’t sell, but I only wrote it to explore an aspect of craft. I’ll be serious about the next one.
It’s psychologically dangerous to strive your hardest at a task and fail. It opens the door to real pain. That pain doesn’t go away. You have to learn to endure it.
1) Take an improv class. Learn about playing to the top of your intelligence. Improv teaches you how to fully commit to material you’re working on.
3) Do something really hard. Run a marathon, sky dive, bungee jump. Often times. we run from pain but it’s the great teacher. No pain no gain. To quote my old wrestling coach, winners are simply willing to do things losers won’t.
4) Read a publicly available script and write notes. Be nasty. Do not send these to the author. Rather, look at the notes and see how they apply to your own writing. Often the things that annoy us most about other writing are the problems we have or recognize in our own. You can’t point a finger at someone without pointing three at yourself.