Before leaving every job I've had, every one, I worried, I agonized, I second guessed myself...

And every new job, every one, within a short time, I thought "I should have done this sooner!"

I think we need to have a bias for moving forward, and I think it is healthy.

That said, I remember a friend who immediately quit their job (for a legitimate reason) without having another job lined up and regretted it. They told me they should have stayed cool, lined up another job first, and then quit.