K.H.
My jaw dropped. Why would anyone this that quitting their job in this economy before having another lined up with a good idea? Does he think you're going to support him now, plus the three kids? Why did he do it without telling you he was going to? That's warped. And to put it on you? I would be freaking out like crazy.
You only have money until October? That's not fine. Fine is a years worth of savings. What if there is an emergency? Car issue, hospital visit? If I were you I'd start going to work immediately, and tell him he has to get a job asap as well.
BTW, are you receiving child support for the childrens' fathers? Good luck, but dang, the fact that he quit without telling you is not a good sign. It's like he knew you'd say no so he did it on the sly. I hope you both are able to find work.