As long as Fox News slobbered over Trump, things were fine between them. But one bad report and suddenly, Fox News is the enemy of the state.
This goes to Trump's love affairs with Kim and Putin. Both men have controls over the media in their respective countries. Trump would love to have that kind of control in this country, but here we have that pesky impediment known as the First Amendment. It pains Trump to no end that he doesn't have the powers Putin and Kim have.
Seems to me that Trump is in a bit of a panic. I'm sure he knows that while he has this core of supporters who will love him and vote for him no matter what, in order to win re-election next year, he must woo those outside that core -- the independents and undecideds in particular. Right now, his supposedly great economy is showing signs of cracking. For most voters, the economy is a major issue. If it tanks, the president will be blamed. This is typical for all presidents, not just Trump. Trump can lie about the economy in his tweets and to reporters, but his potential voters are out there every day having to deal with rising prices, failing retirement nest eggs and maybe unemployment and other tanking economic indicators. They are going to believe the economic news, not Trump.
But instead of taking the negative press and considering that maybe he might need to make some adjustments in policy and perhaps in his persona, Trump is lashing out at the messengers and blaming everyone but himself. This will not sit well with those voters outside his base. They want results. Whining about Fox News and blaming others is not going to produce those results.