Get the zovirax on it. It's too late really, and they will go in there own time, but zovirax might speed process up. Or there's that new compeed patch I've seen advertised? I havent had one in years, so I'm not sure what's best really. Zovirax is best used at the hint of getting one-ice is good at that stage too-and the blister may never appear.
Hope it's better soon anyway. PS Some vitamin C might not go amiss either-dunno whether specifically it will help coldsores but good at this time of year when we're a bit run down!