I have quit twice without having anything to go to, however, I already had about 12 years of experience in various roles. The first time, I was pretty dumb about it, and it could have ended badly. I was unemployed for a about a year and that was mainly due to not being motivated to get back into IT (was totally burnt out - similar situation to yours).
I definitely didn't plan the financials properly the first time, even though I thought I was covered.
The second time I did it was 2 years ago roughly, but I had more of a solid idea of what type of job I wanted (more specifically, did not want - this is personal, and down to you. Remember, you are also interviewing them).
If you have already decided to move (and I think you should based on your description, the last job I walked from seriously changed me in a negative way), then you might consider to slow down where you are, you have nothing to lose, they are clearly not treating you correctly, so I wouldn't feel bad about about half-arsing it. Take sometime to plan your next steps (research roles you want/ do interviews), note what you don't like about the current job and would not want in the next one. Be open minded about all opportunities, even if you think you might not like them (I honestly didn't expect to like my current role at $bigCorp, but its been the best job I have had so far, and this is purely down to my boss and the rest of the small team I work with. This made me realize that I might have possibly found a nice team within that place, but was not open to that, as I had already made my mind up). Again, being open to anything new even if you are not sure is likely going to be positive, as the change of environment and new people will give you a different outlook, which will help, and again, if you don't like it, you can always change. The old school thinking of having to many changes on your CV is dead, no corp has any loyalty to there staff and as such don't deserve it in turn. I of course am speaking generally.
I wish you the best of luck, try to stay positive. And if (like me), you like the herb from time to time, think about knocking it on the head until you get yourself sorted, this was a must for me.