YABU. You are experiencing reverse culture shock and it is truly horrid.
I am a kiwi and have lived in differing amounts of time as an adult both in the UK and NZ. Let me tell you, NZ is no picnic either. It is not paradise, not even close. We live in a beautiful country, granted, but there are serious problems in NZ. Housing is off the scale in Auckland, so bad that ordinary people cannot afford a decent house. The gap between the rich and poor in NZ is horrendous. Honestly, when I returned to live in NZ I had never seen such poverty. People live in awful situations, on very low incomes. Housing is largely inadequate and preventable conditions such as asthma are rife. People are living in total squalor, but that's okay because we live in a beautiful country. Shame most of the locals can't afford to visit the tourist spots regularly.
NZ is a low wage economy, and part of the country certainly reflect that. There are swathes of NZ that are unkempt, houses literally falling apart, some with no running water or electricity but people still live there with little option of moving. There are parts of NZ that might not be quite on the scale of an inner city estate such as Glasgow or London but there are depressing/deprived parts you certainly would not drive through even in daylight.
I get a bit depressed in the UK with consumerism, austerity measures are not nice, the media can be a bit scare mongering/depressing, sure the weather could be better but I prefer the mild all round British weather to raging high temperatures, or living surrounded by snow for 7 months of the year. It's a bit cramped, I can't argue that, but honestly all the space and lack of people in certain parts of NZ are serious inhibiting growth and it's a breeding ground for parochialism, a fear of progress, and totally feeds the NZ is best mentality that I can't abide. I don't feel it as much when living in the UK but when I have lived in NZ I cringed at NZ is best propaganda. Why do we have to tell ourselves we're the best at everything.
Rant over. No country is perfect!