How can I settle unpaid office rent with the landlord?

We are tenants for the past 18 years. Due to the business failure for 3 years, we are unable to pay the rent for now nearly 3 years and waiting for the landlord to say to vacate and go without penalizing us.

However, now they have come to us and saying that we need to pay all the 3 years of rent. Failing to do so, the landlord will send the police to vacate us.

Please can you advise us on the solution?

We just want to move out from here as we cannot afford to pay the rent.

Is there any help for us?