Receiving critiques without taking it personally is hard for most people, I think.
I find perfectionism to often be a part of anxiety. I also find it to be a curse. 😉 I’ve found that consistently reminding myself that nothing can ever be perfect over the years has softened it just slightly (which is better than nothing).
Cognitive Behavior Therapy (CBT) could be a good fit for you to address this issue, as it’s often used to change patterns of thinking.
As for structuring creativity, that’s it’s own beast. Who knows when inspiration will strike? What I know many writers do is to block off a period of time every day, or certain days of the week, and make writing a little more routine. They force themselves to use the time to write, even if not wholly inspired. It’s about being consistent and making progress. Maybe creating a routine like this will help you.
ADDitude Community Moderator, Author & Mentor on Parenting ADHD, Mom to teen w/ ADHD, LDs, and autism