A letter from the family member stating that you need to leave would be an eligible housing crisis for you to receive assistance with start up costs (First, Last, and Security) to move to a new unit.

If you are not on the lease and have not received a Notice to Quit, you would not be eligible to receive assistance with rent arrears if you owe at your current place. All payments are made directly to the landlord as well, so if they are not aware you are currently staying with the family member, that could also raise other issues for them.