My ex-gf is still threatening me after 5 months to end her life for break-up

We had 6 years of long distance relationship. We used to chat and barely call. We only met once in person in 2019 and had physical relation only once with mutual consent. We had many fights over very small things and ultimately I felt it is not working between us. I told her that I can't continue and we broke up. Then, she started threatening me for ending her life if I don't come back. It's been 5 months now after breakup and she is still threatening me and I am living in fear each moment. I wanted to block her after her bad rigid thougths but she started contacting my friends and family and affecting my work as well. I explained her that this is not right. She kept on threatening me with same and asked me to come back. Her family member knows her suicidal tendencies too but they are not doing anything about it. I know if something happens tomorrow, they will blame me. But, I did everything to help and kept explaining her that these kind of thoughts are bad. But, she is sticking with her wrong mindset. What should I do now?