Mental harassment

I want protection from my sister in law who is giving me mental torture from day one since i got married 27 years ago. Her husband had kept her attacks in check a bit, as he knew his wife's nature, but after his death, she n now her 31 yr old daughter is forever interfering in my marital life. My husband has been unsuccessful in all the businesses he tried n we live on the rent that the builder pays us for developing our house. My late mother in law had transferred the house in my husband's name, but for some reason of his he added his sisters' names too. Now, the dominant sister is full on abusing n accusing me that i hit her pschizophrenic sister who is 62 years old n suffering from hypothyroidism. I have been caring for this patient sister in law ever since i got married while the other sister in law used to tell her mad sister that she would have to wash my clothes n look after my children forever now. This is just one example of her trying to create turmoil n chaos . Further since my husband doesn't earn livelihood, she pressurises him and create rift between me n my husband. Now she and her daughter are threatening me to put me behind bars.i have lodged an NC with the local police against my dominating sister in law but daily torture hasn't stopped. Please help me retain my sanity