My fathers family (mother and sisters) tortured my mom alot so much so that It has taken a toll on her health.The fathers sister lives in the house my dad built and wont leave even when we want to sell it.My mom has sacrificed and saved every penny to build it and now our condition is not good because of them.Am I still supposed to maintain my blood relations?
Yes! What they are doing has nothing to do with being good to them.
You must at least give them a phone call or text message once in a while and say salam whenever you meet.
If your father is dead, the house belongs to you and your mother if you have a brother or you parental father is alive. You can go to the police and ask them to leave as they have no right in living there nor in forcing themselves on you.