I know the title is a bit extreme but I am really distressed with this but I want to know if there is anything I can do.

Basically my housing association is forcing me to move out because I am not down as main tennant (even though I should have been from the start) and my sister is, but my sister now wants to move out.

They have now give me until December (which is kind of them) to find suitable accommodation and move out. Is there anything that I can do to prevent this from happening.

Note: I have already advised them I would be happy to do a right to acquire to purchase the property from them. But again due to me not been a main tenant they said this is now allowed without my sisters name on it as well.