What is the Solution for mental harassment

I am fed up of bearing the mental harrasment by my in laws.My mother in law and sister in law take turns and harass me.I have a son who is 7 years old.They treat him badly in front of sis-on -laws son.always comparing and dejecting my son.my sis in law never leaves any opportunity to torture me.everyday she will be at our home plans for a fight.though she stays next lane along with her husband,she will have her breakfast or lunch or dinner from here along with her son.my husband doesn't shift house from where we are staying.says we need to take care of his sisters son so his parents have to stay here.so I should bear what ever they do.I am a working woman and so I reach home at 5or5:30 only.my son comes from school by 3:30.mother in law prepares new dosas for her daughters child and give morning made idlis or previous days idlis to my son.before I come she also scolds my child for no reason.Sis in law and her husband are financially sound too.when I say I will complain to police regarding their mental harassment towards me they are saying that they very well know how to come out of it.my mother in law and sis in law knows how to act in front of others too and make others believe them.my husband dosnt bother even if i say what they are doing.he inturn blaming me saying that i donno to adjust.he also says that there are people who are killing their daughter in laws,here noone killed you ,so what is your problem?no one is there to support me.What should I do?