Hi Sandi Matic.
Indeed, server location is in US and that matters.
On the other hand I see in google search result versions of your website: with www and without www. I see also this at the end of google results:
"In order to show you the most relevant results, we have omitted some entries very similar to the 89 already displayed.
If you like, you can repeat the search with the omitted results included."
so this means you have some amount of similar content.
In code I see this: but your website is dedicated to New Zealand right? Change this (and all other) to en-NZ. Setting hreflang can help too.
Also you have little amount of linking domains (weak or weaker domains after new penguin 4). Worth to do is linkbuilding.
Another errors are meta descriptions are part of main content, heading h1 doubled, etc. To check all, page by page seo audit is needed. Even if you had it before, now you have to fix those onpage things to get better serps/traffic.