Received 3 day notice to perform covenant or quit notice from my landlord today, as I am subletting my apartment. What do I do?

I am indeed subletting through airbnb, however only because I lost my job and did not want to get behind in bills. Have paid my rent on time always for the past year. Not subletting would be not having enough money to cover rent, however I might get into a sum when taxes are returned. Is there anything I can do here to delay the process, what would the next step of the landlord be? Is there an official response I should be giving? Further details: - I have been subletting the full unit, although I am unsure what actual proof the landlord has - I do not think my unit is rent controlled - As said I lost my job and am making ends meet by subletting. - The issued the notice yesterday evening.. Which makes Monday the 3rd day.. Why would the issue it before a weekend..