Transition to self employment

Hello

I am a salaried worker ($90k) who has an opportunity to start self employment in a niche area that pays well.

However, I have no savings and a mortgage which could be reduced if necessary. I pay more than the minimum.

It would be about 3 months before I likely start receiving any income and will be doing my own billing/tax etc through Hnry.

Are there any services that would aid the transition or provide some level of income while working, but not earning?

I’ve always worked and am unsure what, it anything, might be available through WINZ. I know there is a stand down if I resign.

The only thing holding me back is the absence of income for a short period, (which all went into the house deposit).

All advice gratefully received, thank you in advance!