Difficulty has changed. Our profit will fall?
Difficulty drop equals more coins which equals more or equal profit most of the time. Difficulty rise equals less coins. However block reward is slowly decreasing so you'll be getting less coins overtime and less profit but that corresponds to price of coin.
I was making before changing daily 1.2 million. Current 500,000 seems. Fine?
Depends on your hash rate and current difficulty and block reward. Right now with 300khs 155k block reward and a difficulty of 1.9 you should be getting roughly 500k/day.