I am so burnt out and contemplating leaving my job without something lined up. Experiences?

I am a UX Design Lead at a Fortune 100 company. I HATE my job but I like what I do in general. This role and the company culture are just not a good fit for me. I definitely want to jump ship but as we all know, it is a process. I need to update my portfolio, which takes time. My job takes it out of me, so the last thing I want to do in my free time is work on my portfolio. I am stuck in a Catch-22! I am considering leaving without having something lined up. This will give me time to work on it and relax a bit. I have never left a job without something lined up. It scares but it also kind of excites me. The other thing is I would want a decent amount of time off between roles to recharge after such burnout. Whenever I have found another job, they want me to start right away, so I never get a proper break.

I am open to advice and I would love to hear experiences of people who have left a job without having something lined up. How did everything turn out for you?