I am being mentally harassed by my in laws.

I am 27, being married more than 1 year now, I am being continuously harassed by my sister in law who is married, which is causing harm to me mentally and damaging me a physically. I am not able to cope with situation & my husband doesn’t know/not willing to take action/solve the matter, knowing that it’s clearly her fault. I have been approaching my husband and in laws with proofs that I am able to gather.. but they are not willing to take action keeping aside the love for their daughter/sister. But this is harming me in so many ways. I am continuously facing mental torture from her side and she is manipulating my husband who is unaffected till now and manipulating my parents in law to do the same as she is doing towards me. I feel anger towards my husband that he doesn’t take action this and towards the dishonour and defamation she is causing me. Recently it’s getting unbearable and I am either thinking Of getting divorce or killing myself because of this pressure.What should I do?