I'm not rich, and really wanted to get back into photography after a long hiatus because of cashflow, so sort of where you are, I've been. I was into film, which had a ridiculously expensive ongoing cost (film, developing, etc), and just gave it up. I realized that the digital world allowed for the hobby, eliminating a major expense associated with it.
With that in mind, I think right now, your main concern should be getting your highest net in pocket cash. While a financial advisor (of which I am not) would probably tell you to sell it all and give up photography until you get back to a position where it is affordable, I think there are other ways.
Here's what I did to get back into it, and it may give you a way to stay there, and stay afloat.
My wife gave me a very small budget for a camera. That was $150. Hmm... not many Canon Dslr's out there for $150. I had a couple of EF lenses that would carry over from the film days, so I just needed a body. I researched the older digitals, and found that I would be satisfied with a couple of bodies that seemed to sell close to or at my price range (Rebel, Rebel XT, 10D, 20D, maybe one or two more). I watched, and I watched, and found a Rebel XT that I was able to grab for $81 + $9 shipping. Sweet! Is the Rebel XT a 50D? No. Does it take good pictures? Yes. Was I able to get into the Digital SLR world, and not have to sleep on the couch? Yes! So for $90 (plus a couple of bucks for a CF card and reader), I have an 8mp Canon.
If I were you, I'd sell the 50D, the 70-200mm L, and the 430ex, and buy an older body (XT, 20D, maybe even a 30D) the 55-200ef-s, and a Yongnuo flash. Keep the 18-55, as it's a good lens, and the 50 isn't valuable enough to justify selling. You should be able to get $500-$600 for the body, another $500 for the lens, and $200 for the flash. Spend $150 on the new (used) body, $150 on the 55-200, <$100 on the flash and you've netted yourself $800-$900. That's rent, or a decent car repair, or a couple of months worth of groceries. And you still have close to the same equipment (I'm not saying the XT/20D is equal to a 50D).
You sound young (20's). You have plenty of time to buy the best that you can afford. The equipment you have, you didn't need, it was what you wanted. Now you need cash more than you need higher-end photography equipment. Step up and step down so you can stay afloat. Then when things are better, buy the 5D and everything else, because by that time it will be an affordable camera, and pay for it with cash on hand.
Contrary to the very popular belief that you have to spend thousands to take a decent photo, you don't. IMHO, if you aren't making money with your camera, there is no need for the top of the line.