There's already been a ton of awesome advice given here, but please don't make any quick decisions just because it would give you time to paint more. Painting more isn't going to pay your bills! You need to be able to SELL more, and sell enough to pay your bills on a regular basis.
Unless you already have the financial means to not have to work and are doing so perhaps only for health insurance or the like, this really isn't an optimal time to be giving up a secure income. The national/international economic climate is a MESS right now and it's not projected to get better anytime soon. Sigh.
Calculate your monthly expenses. I'm sure it's MUCH cheaper to live in Minier, Illinois than in Sacramento, California (I did look up your town to be sure it wasn't a Chicago 'burb!). I've felt for many years that I would only have to make $50/day to keep my bills paid and have a little extra, even here in California, so it's likely much less than that for you. Read some of Suze Orman's books! She tells it like it is! Someone posted here that you should have enough savings to keep you going for 1 month. I hope that person never loses their job! 6 months reserve is really the LEAST you should have and 8 to 10 months reserve is much better. If you owe on any credit cards (in a big way), get them paid off before you quit your job. Is your job one where you can go to part-time, even on a temporary basis? This would be a safe(r) way to test the water about trying to make it on your own without a day job.
Your work is lovely and I think it might lend itself to greeting cards and other licensing options, if you're inclined to go in that direction. Google for "licensing reps" or go to the Chicago Gift Market (
http://www.shopchicagomarket.com) and look at the wares and see if you think your designs would work in a similar context.
Do you show your work in any galleries? Again a big city would probably be a better option ... there might be galleries in Bloomington or Champaign-Urbana, and definitely Chicago, St. Louis, Indianapolis, or Des Moines! What I'm trying to say here is don't put all your eggs in one basket (i.e., don't count on Etsy to provide enough income). Get some of these other things set up first and then Etsy can be the icing on the cake!
Good luck with whatever you decide to do!