Mindset is a powerful tool when it comes to writing. As a writer myself, I've been the victim of being critical of myself. "Is this good?" "Did I mess up?" "This is hard!" "I suck!" "I'll never make it as a writer!" "What if no one likes this?" Ever had any of those mindsets? I know I have. Nobody says that getting your script sold would be an easy task. Believe it or not, most professionals are in the same boat as you.
Think about it, do you really think James Cameron can write a film and sell it on the first try? No. It's like when actors audition for a role for a movie. Just because they're famous doesn't mean they're going to get the part. They still have to audition for the part like they've been doing since they got started. As a writer, it's pretty much the same thing, but it all starts with the way you think.
When you're working on your script, it's critical that you're not being hard on yourself. I know when I write, I can sometimes think, "Wow. This is difficult." Sometimes, it can feel like that. For example, a few months ago I was working on an entirely new script, hoping it'd be another feature, and yet I struggled with it because I was writing a different genre and the passion for it faded throughout the month. Sure it's a 60 page short feature, but I don't see anything else happening with it. Perhaps it's because it was the story that sounded complicated to write or that I've never wrote a horror film before. Am I going to turn it into a feature? Probably not. But guess what? I made the goal of making it a 60 page short feature and I accomplished the goal, all thanks to changing my mindset.
It's important that you're aware of your thoughts and why they're coming up. If you dive into a script thinking you're not good enough or your story isn't good, other readers are going to look at it and think the same. However, if you change your mindset and think, "I'm enjoying the process." or "I can't wait to see how this would play out on screen." then everyone else's opinions won't matter. Someone could still think the script needs work, but you're the writer. You created something you're passionate about. You took valuable time out of your day to sit at your computer and type for an hour or so. That's an accomplishment right there!
So, no matter what happens, please be kind to yourself and know that your hard work is going to pay off in the end. If you want to make it into the industry, you have to have a positive mindset and face those negative thoughts. When I have negative thoughts about myself or my projects, I stop what I'm doing, change my inner thought, and continue writing. At least you're not facing any deadlines, right?