We've all had to deal with tough critics, and sometimes your toughest critic lives in your head.
Do sit with that feeling of not being ready, and gently question it: not ready for what?
With regard to writing, it sounds like you have a process that isn't working for you. That's not something wrong with you or with your process; it's a mismatch, like someone putting on a shoe that's much too large for them.
You have to pace yourself, like an athlete with an injury doing slow small exercises before returning to marathon running.
As with writer's block, what's getting in the way of self-promotion is not practical but psychological.
I love semicolons; they're great. The issue is what you're doing with language and content that leads to the use of so many of them.
You can't thrive by only making art that feels safe and easy. But you also can't be brave all the time; you need rest, and play, and learning, and sustenance.
Nothing gets in your way more than a creative writing degree and a lot of practice doing other kinds of writing, both of which fill your head with all sorts of ideas about what writing should be like.
If you're feeling the urge to go back and fix (or despair over) what you've written already, and if it's getting in the way of powering on toward your goal and your deadline, this post is for you.
Self-criticism is incredibly painful, because we know where all our own weak spots are. But by that same logic, we can also be our own best allies, cheerleaders, and friends.