Help me keep my kids home

I am a single mom of three boys. Ive been a stay at home mom most their life. I got a job in HVAC two weeks ago to start trying to pay the bills on my own. My now ex boyfriend claimed to have paid July's rent. Even when asked over an over if he did or if i needed to he reassured me it was paid. Yesterday July 10th the landlord calls an asked where the money was an filled me in that he never gave her any money. So now i have until friday July 12th to come up with 985. I have 400 of it but need some help with the rest. This is me an my babies home. We are finally in a stable home after a rough divorce. I dont want them to lose this. If you find it in your heart to help any amount will help tremendously. Thank you in advance.