Ditto. Very important to not let rust get a foothold onto that bare metal. What tgiovan said: Just get a can of ANYTHING to cover it. Primer first would be nice. Even though you're just covering it up til you can get some proper paint on it, featheredge the area where the paint came off. Use maybe 220 grit. Then prime, sand again, and paint. Hell, just to waterproof it (primer is porous, and will allow rust to form if left unpainted) I've shot a bit of clear over the primer itself!
Have fun,
sorry to hear about your crash.
-W-