It sounds as if you have been on quite a journey already and built a number of learnings about what has and hasn’t worked for you across that time.

I am not totally sure from what you have shared if you want to put any more money into the business yourself or really need to find a partner in order to continue. Either way, a strong business plan for the next horizon of your venture will be needed. Either to guide your own activities or to tell the story of what you believe your business can achieve with the right support and funding.

There are some great templates to complete that process and you can keep it light touch and relatively short as long as it is punchy and clear.
Who is your target market
Why will they buy your products
What sales channels and marketing investment do you need to build awareness and convert to purchase
What is your supply chain and go to market model
What are your financial projections

I am not sure what area of NZ you are in but your local council provider (I know ATEED offers this service in Auckland) or this link will give you some good templates to kick off.

Given what looks like your special niche you might then approach specific potential partners who share your interests and vision or even try something like Snowball Effect and crowd fund some support for the next stage of business development.

Good luck!