I don't think you're in big trouble, but I hear a lot of distress in what you're saying. I'm not a lawyer, a psychiatrist or anything else on television--I'm just giving you my 2 cents without much in the way of critical context.
That said, it seems like you need to back up, take some of the pressure off of yourself, and get your personal situation stabilized a bit more. Once you do that, it sounds like you'd be in a lot better place to figure out if an MBA is going to meet your expectations and if you want to and feel up to improving your GMAT score.
In terms of number of retakes, I'm not sure how much this matters. I don't think you want to spend your life retaking the GMAT, but if you want to give it another shot and can devote the time and effort effectively, then why not. Follow your dreams.
At the same time, I think it bears mentioning that no single degree is guaranteed to patch up anyone's career progression. Sure, you go to HBS, maybe everyone there graduates and has an amazing career (actually, there's the disgruntled guy who wrote that book I can't remember the name of -- so we've already disproven that notion). I think for most people it can definitely improve their progression--that's why we're all here right? But there aren't guarantees and some people probably get an MBA and regret it. My wife probably regrets her JD.
Which is all to say, it sounds like you're putting an inordinate amount of pressure on yourself and moving with a bit of desperation. Careers take decades and sometimes people take years to get theirs where they want it to be--unless you're as old as me, I'd wager you have time.
So get a new job, get started off on the right foot, get comfortable and then think about attacking the GMAT and application. You have a lot of opportunity to improve on verbal, right? If you want to take a break but still work verbal, start reading some well-written English-language authors (Martin Amis blows me away) or The Economist. At some point when you're ready, start chipping away at your verbal. Plan for more time than you think you'll need to keep the pressure off--remember; it's a race not a sprint and you have time.
I don't think just trying to barrel through and move your score up to 620 is going to help you--you still have to deal with the application, interviews and school, and I think you need to have some peace of mind and confidence to do all these things to the best of your ability.
Anyway, I'll get down off my soapbox now
Best of luck.