Check engine light blinking on and off means it's a seriouis misfire. Continuing to run will probably toast your cat converter as it can overheat, literally starting a fire with the unburnt fuel.
Are you losing coolant? Are you sure the white smoke isn't just water vapor from first starting up? Head gasket could be the problem. A pressure check of the coolant system, cylinder, and/or a leakdown test would shed more light.