I was exactly in your situation 2 months ago - I was on the verge of drafting my resignation letter as I wasnt happy with my Project for various reasons and could not take the pressure and stress anymore.
I had a look at my finances and though I could support myself for upto 6 months without any problem, I asked myself if I was taking an escapist view out of my problems - And decided to stay for another month and do the right things , however difficult or stupid, and then take a call in a month. In that month, I had a chat with my Line Manager and my Mentor and they supported me and took actions and suggested ways to get out of the situation I was in. Now, I am glad I made that decision to give it another month and work things out, rather than just giving up and resigning.
Coming back to your question - I know of ZERO people, in my 8 years of Consulting life, who resigned without having an offer in hand, or an alternate plan like travelling or career change or relocation , etc. But that doesnt mean you shouldnt do it - If you have given yourself that last extra chance of making things work at your workplace and it still hasnt improved your situation, I dont see why you shouldnt resign and look for something which will give you a better quality of life and job satisfaction - But make sure you can support yourself financially and emotinally for the next 3-4 months, as sometimes it can take that much time to get a decent break, even if you are well-qualified and well-experienced
Hope this helps - Good Luck