[Fauxreal]

Not having a contract is the problem in this case. That and your brother would do this to his sister.
No offence but it sounds like you brother is a testicle. (He's hanging out not doing anything.)

Not having a contract puts you in a bad spot. You could sure him for being your landlord and screwing you over. But at the same time he could call the cops and say you are squatting in his house because you don't have a contract to live there.

Either way. It's not good.

It's she said/he said at this point without that legal will document and lawyer.