is it possible to re-use a o ring head gasket? it wasnt blown, i just took head off to replace the head, gasket looks good. is it possible to re-use it????

Yes, and often it works fine. Beware of the downside though if it leaks; you may pull unwanted stuff into the cylinders or cooling system. (No guarantee on new O-rings either; just less likely.)

is there something i can put on the o-ring to help it re-seal?

Just clean them with something mild (like WD-40 or injector oil) and clean the groove ans mating surfaces. Just make sure you handle used ones carefully so you don't stretch or twist them. Replace them just as they were. If in doubt, use new ones.