I am on the same boat as you. I will be applying this fall for MBA programs and I just quit my job. I worked about 90-100 hour weeks, and did not have any opportunity to sit down and focus on my studies. I realized I had to quit when my first practice test I scored a 650. I studied through my phone using apps for a few weeks, then retook it and scored a 630. That's when I realized this was not going to work. I quit my job recently and spend approximately 8-10 hours a day studying. Within a week I took a practice test and I just scored a 690.
I think it is personally worth it for me because
A. I had money saved in the bank to quit and have 0 financial responsibilities other than rent. (no family to support)
B. I did not have any time where I could sit down somewhere quiet and study for long periods of time
C. I have the motivation to study normal work hours.
I will take the GMAT at the end of June, and then finish my applications then will most likely travel then look for a job to hold me over until school starts. Hope this helps and you're able to make an optimal decision for yourself.