what do i do?

my bf always gets his tax retrn in 24hrs of filing. has for 10 years. he didnt qualify this year. the rent is 13 days late. a few days ago i panicked and told the landlord that i sent the check already. she stopped by today and left a 3 day notice to pay or she wil begin the eviction process. she said the bank doesnt care about my problems i have been having (death of my friends dad who i have known for over ten years, my daughter was diagnosed with cerebral palsy, the older child is causing problems). we are due to have the check in the next week but it doesnt seem to matter. his ex wont pay child support and he wont go file for it. we dont have the credit to get a payday advance, plus he owes money to a payday advance company form years ago.
all we need is 900 by the 18th, 2 days before the expected tax return. i dont know what to do i screwed up by panicking and lying.
the landlord stopped by without notice at 8 this morning! so im sure she will just ‘drop by’ again later today. so i know she will ask for the ‘returned’ check. so am i screwed?