Of course I get angered by some of the stories I see in the news - who wouldn't? - but also know that they aren't the whole picture. Research has shown that people read about the tiny number of child murders (I'm not diminishing the horribleness of those acts) and walk away with the impression that it's rife when of course it isn't. And that goes for a lot of the negative things that get reported.
Yes I hate PCness when it gets ludicrously out of hand, such as councils renaming xmas lights as 'winter lights' for fear of "offending" local muslims and hindus - even when the muslims and hindus then protest that they aren't in the least offended. Clearly, that sort of thing is councils being downright stupid. But it's not as though it's happening everywhere, despite the impression we may get from the media or our own imaginations. And when it does happen, rather than grumbling or emigrating, we should make a big noise about it, protest, bombard the council with letters and phone calls, make our thoughts known. It's very distorting to say "no-one can truly say what they think anymore" as though we're living in communist China.
Your choice of words is very telling, pitstop - "All I seem to read about are murders etc, immigrants etc". "It seems as if the country has gone mad". Emphasis on the SEEM. By cherrypicking each murder story and every single crime committed by immigrants, and every example of crazy PCness, yes the media do make it SEEM as if the UK has "gone mad". Don't get me wrong - the country has faults, stresses, strains, weaknesses, it's far from perfect. But we are not about to tumble into the abyss.