This is really one of those YMMV scenarios, and, while I was chiefly responsible for a household of two adults during my transition from Working For The Man to Living in My Bliss (which, for the record, is more unquantifiable peace than constant state of euphoria), I never had to support kids doing this.

The first step, believe it or not, is what you're doing?noting your dissatisfaction, odd feelings of jealousy, exhaustion at the prospect of doing your own creative work. Really note--and own--them.

Next, you need to carve out a little private, dreamy time. Doesn't have to be a lot, but it has to be solo and it will help enormously if it's regular. Say, a 1/2 hour solo walk per day, with no agenda (e.g., hoofing it to the 7-11 for milk doesn't count). If you can meditate, knock yourself out; most geeks I know (myself included) have a lot of problems turning off monkey mind without engaging the body in some activity. This will help free up your brain a bit, and give it room to breathe and stretch and play, things it is probably very good at doing when it's not being whipped into submission by The Man.

As for figuring out what to do, this is where things get a little Joseph Campbell-y. There is no one path, one way. Hopefully, people will chime in with tricks & tips. Maybe you should pose the question at metafilter (maybe it's already been answered!) I think books are great for this, but music or art or something else that fully engages you would probably be good, too. NOT the web! As much as I love it for tips and tricks and even community, there is no substitute for you and the Truth, up close and personal. "The Artist's Way" by Julia Cameron helped me enormously, but it is verrry arty-farty. But a couple of the principles from it--the Artist's Date (where you take two hours once a week by yourself to "feed" yourself) and the Morning Pages (basically, a daily longhand brain dump that serves as mental palate cleanser and, long-term, road map) work like gangbusters.

Some other random things that helped:

-- go to a great bookstore and let yourself be drawn to whatever. Read, don't buy. See where your body pulls you. (Sorry, woo-woo again, but that's my experience with the process!)

-- start doing little things differently: if you always take one route to work, take another. If you always drive, take the bus. If you always have coffee at 11, have tea...or Hawaiian Punch, or nothing. Breaking your routine helps you bust out of old modes of thinking in lots of ways.

-- remember to keep having fun! Seriously--it's easy to get too serious about this. The stakes seem so sky-fucking-high, it can get a little intense. Breaks are good. Play with those babies. Get it on with the wife (in a different place, of course!)

Of chief importance throughout this process is P-A-T-I-E-N-C-E. It took me 10 years to fully transition from lauded-but-miserable advertising copywriter to the happy-but-not-so-sought-after free spirit I am now (sort of a hybrid actor/writer/designer/pundit). That was 10 years *after* the dissatisfaction had mounted to stratospheric levels.

The money issue is real. I found that I don't need as much to make me happy anymore, but again, I don't have anyone else to support. (I unloaded that husband along the way.) Again, YMMV. But you might also find you don't need to leave your job, or some other job, but restructure it. There's more than one way to skin a cat (although why anyone would want to skin a sweet little kitty is beyond me).

The point is, do some things to shake yourself up and open yourself to the possibilities of ANYTHING that could happen. You never know what your ideal life will look like.