EDIT Ok, so MSE has correctly reversed thing during night, but things seem to continue this morning (reputation). But of course, I have no more proof than yesterday. And with the added benefit that moderate downvoting has more chances to look normal (after all, somebody may perfectly well dislike these two posts). Nice.
@Martin's link says everything that needs to be said. Basically: if someone is really targeting you for serial down-voting, the system has ways of finding it out and automatically refund you reputation. So just take a deep breath and wait a bit. If by tomorrow this time the situation has not been resolved automatically, flag a moderator and we'll look into it.