If you have to travel to a specific place during a specific time, there isn't much you can honestly do and might as well not worry about it. There is no real rhyme or reason with airfare pricing other than knowing where peak season is or that tickets booked within 30 days generally are priced higher (at least from personal experience).
But like another poster said, if you were OK with the price before then there's no point in getting upset about it. Or book with miles, the price in miles only gets worse!