You are not alone first and foremost. The ability of a bank to request additional funding is in my view a flawed system in these circumstances- the UK government changed their system immediately when they realised the bank’s were effectively double insured for the risk, first from company and guarantors, and then from the government- but that unfortunately is the situation we are in.
You seem to have done a lot in a short period of time and great to here your primary suppliers are supportive, but the reality is, that if you don’t have enough cash to go around then a more drastic alternative might be needed.
There is currently a Company Compromise option that you could consider – which is effectively a deal your offer ur creditors to defer payment over day a year to ease cashflow constraints. And shortly we will have the Debt Hibernation Scheme, but I think that is still a few weeks if not months from being formalised.
My best advice would be to seek advice from an accredited insolvency practitioner who can guide you through the options and who are experienced in all restructuring options – experts for exactly this situation.
Accredited practitioners can be found here https://www.ritanz.org.nz/search?firm=&surname=&city=&status=2
You will find me on that list / connect with me if you would like once you have done some research.