Your longer-term resolution, which I hope to share both with you and people whose present position resembles your position back in February (so that their position in October does not resemble your position as of this moment), is to improve the management of your business or, if you are unable or unwilling to do so, to secure gainful employment as a computer programmer, and trade the upside for predictable paychecks every 2 weeks until such time as you have financial/social/etc resources to survive natural variation in cash flow.
You're a freelancer. Variability in payment schedules is something which your business needs to be able to deal with.
You manage a business, and you should comport yourself as such, rather than as e.g. a college student who occasionally works for spending money. This implies, among other things, radically raising your rates, securing appropriate credit to smooth out your cash flow cycles, securing appropriate savings to smooth out your cash flow cycles, securing social and professional relationships such that you have them available in leaner times, and locating the business somewhere conducive to success at it. I express no opinion on whether Vancouver is that place, but if you've got no support network there and are at the margins of Canadian society, I would suggest rectifying that.
You should work on your pipeline such that you've always got some engagements which are in the pitch stage, some which are in the execution stage, and some which are in the "get the final invoice paid up" stage.
You need to increase your billable efficiency to more than the number you think is required for meeting your monthly expenses, because if you shoot for poverty level incomes, you will be poor when the business performs at plan and destitute when it does not. Your minimum viable number is not $600 a month. It is closer to $3,000 billed a month. This is the absolute "pack it in if you cannot hit it" minimum number -- a successful freelancing business should be billing much more in the current environment.
I assert, without fear of contradiction, that you do not charge nearly enough for your services. You need to charge more, substantially more. You probably get bad clients and bad projects from something like oDesk. Do not get bad clients and bad projects which pay you no money. Instead, network actively and get better projects from better clients at the prevailing wages for professional work.
P.S. The best clients will not respond well to hearing about you being a hair's breadth from financial disaster, because this does not happen to professionals. It suggests a lack of professional competence and will, therefore, impair your ability to land engagements doing professional work. In keeping with the "comport one's business like a professional" strategy, you will want to avoid sounding like you need to get paid ASAP.