Do you have any advice for me to overcome perfectionism as a writer?

I'm asking specifically about writing fiction.

I need to write a lot in a short time. I'm a perfectionist -- a therapist once called me obsessive. Sometimes I spend hours on just a few paragraphs. I eventually make good paragraphs but that is not very productive. Deadlines fly by, I become anxious and stressed. I wish to write more, even if it's not as good. Better to have something to edit and correct than nothing at all.

I reckon that a book is not made of 100% perfect phrases. At some point you gotta lift the house, even it is not as pretty as you want. I want to experiment with writing more freely, finding ways to overcome my self-criticism and impostor syndrome. I see people writing 3000 words a day... maybe I don't need to write that much, but I envy them. I often don't write more than 500 words per day. This is just not working for me as a professional writer.

Maybe I could try something like stream of consciousness. But I don't know. Looking for advice. Not necessarily on literary techniques, but also on how to put myself in a position to avoid self-recrimination, let things flow a bit more. I'm looking for a better psychological outlook. Right now I edit my stuff so aggressively that I transform pages into tweets.